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OR   THE    ^-ATUJiAL   CLASSIFICATIONS: 

«  *         ^ 

OF  MIELL S(^Dj SWELL-FISH ^ 


'StiOiruvTi  del 


/:'  l-'indefL  fc. 


FEINTED  FOH  lOlfGlUK,  OHlffi.BaoW^^  GREEN.  &  I.OHGiKNS,  Pim-JOTOSTIU,  BOW, 
Jj-SD   JOHlir  1,333,011, -OypEB    GOWER  STREET, 
1840. 


CONTENTS. 


PART  T. 

A    GENERAL    SURVEY    OF    THE    TESTACEOUS    MOLLUSCA. 

CHAP.  I. 

Introductory  Observations.  — The  Mollusca  in  general.  —  The  Characters 
and  Analogies  of  the  three  primary  Divisions  or  Classes  ;  namely,  the 
Acrita,  the  Radiata,  and  the  Testacea —  Notes  on  the  Bibliography  and 
the  existing  Classifications  of  the  latter  -  -  -  Page  1 

CHAP.  II. 

On  the  Testaceous  Mollusca  in  general,  the  primary  Divisions,  and  their 
Analogies  to  the  Vertebrata  and  Annulosa  -  -  -  26 

CHAP.  III. 

On  the  Order  of  Gasteropoda,  its  primary  Divisions,  and  the  Characters 
and  Analogies  of  the  Muricidce  and  the  Turbinellids  -  -  53 

CHAP.  IV. 

The  Zoophaga,  or  Predaceous  Shell-fish,  continued.  — The  Family  of 
Volutida;,  or  Volutes  -  -  -  -  -  97 

CHAP.  V. 

The  Predaceous  Gastropods  continued — The  Strombidce,  or  Wing- 
Shells  -  -  -  -  -  -  -136 

CHAP.  VI. 

On  the  Phytophagous  Tribe  of  Shell-fish The  primary  Divisions  or 

Families — The  Helicidffi,  or  Land  and  Freshwater  Snails  -  158 


Vlll  CONTENTS. 


CHAP.  VII. 


The  Phytophagous  Gastropods  continued.  —  The  TurbidaD,  or  Marine 
Snails  -  -  -  ...  Page  1V.'> 

CHAP.  VIII. 

The  Phytophagous' Gastropods  concluded.  —  The  Haliotidae,  or  Ear-Shells, 
and  the  Naticidie,  or  Nerits  -  -  .  .  £28 

CHAP.  IX. 

On  the  Aberrant  Tribes  of  the  Gasteropoda,  —  namely,  the  .Scutibranchia, 
or  Limpets;  the  Cyclobranchia,  or  Chitons;  and  the  Pteropoda,  or 
Crystal  Shells  -  -  -  -  -  -  241 

CHAP.  X. 

On  the  Order  Dithyra,  or  Bivalve  Shells —  The  Affinities  and  Analogies 
of  the  Unionidas,  or  River  Unios  -  _  .  .  253 


PART  II. 

A  NATURAL  ARRANGEMENT  OF  THE  UNIVALVE  AND  BI- 
VALVE SHELL-FISH  COMPOSING  THE  ORDERS  GASTERO- 
PODA AND  DITHYRA  OF  THE  CLASS  TKSTACEA       -    29^ 


EXPLANATION  OF  TERMS  USED  IN  DESCRIBING  THE  SHELLS 
OF  TESTACEOUS  MOLLUSCA  -  -  -    391 

APPENDIX  -  -  -  -    405 


A  TREATISE 


ON 


MALACOLOGY; 


OR 


SHFTT.S    AMD   SHFT.T.FTSH 


ERRATA. 

Page  192.  line  3.  from  bottom,  for  "LucideUa"  read  "  Lucidula." 
193.  lines  19.  and  36.  for  "  Heraicycla"  read  "  Polygyra." 


CHAPTER  I. 

INTRODUCTORY    OBSERVATIONS.  THE    MOLF.USCA     IN    GENERAL. 

THE    CHARACTERS    AND    ANALOGIES     OF     THE     THREE      PRI- 
MARY    DIVISIONS     OR     classes;     NAMELY,    THE      ACRITA,    THE 

RADIATA,  AND  THE  TESTACEA.  NOTES  ON  THE  BIBLIOGRAFHY 

AND    THE    EXISTING    CLASSIFICATIONS    OF    THE    LATTER. 

(l.)  In  our  last  volume^  we  completed  the  survey  of 
those  great  divisions  of  animals  which,  from  possessing 
a  bony  skeleton,  are  called  the  Vertebrata.  Our  pre- 
sent treatise  will  he  devoted  to  a  far  more  numerous,  hut 
less  interesting,  assemblage,  —  namely,  the  Mollusca, 
or  soft  animals.  These,  with  few  exceptions,  are 
either  inhabitants  of  the  ocean  or  of  fresh  waters.  The 
majority    are   little    known    even    to    naturalists  ;    and 

B 

f 


^  SHELLS    AND    SHELL-FISH.  PART  I. 

hundreds  of  our  readers  may  pass  their  lives  without 
seeing  one,  save  the  slugs  in  their  gardens,  or  the 
empty  shells  they  once  inhabited.  Their  aspect  to  the 
ordinary  observer  is  strange  and  unprepossessing,  with- 
out either  the  gracefulness  of  form,  the  activity  of 
motion,  or  the  richness  of  colouring  which  ornaments 
insects  and  vertebrated  animals.  Their  manners  and 
economy  scarcely  come  within  our  cognisance,  for  their 
actions  are  carried  on  in  an  element  we  do  not  in- 
habit ;  hence  they  are  rarely  witnessed,  and  a  few 
partial  details  is  all  that  has  yet  been  gathered  to  eluci- 
date their  history.  Their  soft  and  slimy  bodies  cannot 
be  preserved  so  as  to  interest  us  even  by  their  appear- 
ance, or  to  become  objects  of  beauty  or  of  popular 
interest ;  they  are,  in  short,  almost  passed,  ''  unheeded 
and  unknown,"  except  by  the  eye  of  Science. 

(2.)  The  object  of  the  series  of  volumes  we  are  now 
producing,  is,  to  give  to  the  world  what  has  never  yet 
been  attempted,  — a  philosophic  survey  of  the  works  of 
nature,  based  upon  the  harmonious  relations  which 
every  part  bears  to  the  whole.  Partial  systems,  ap- 
plicable to  one  branch  only,  and  a  crowd  of  anatomical 
facts,  have  been  either  omitted,  or  but  slightly  touched 
upon,  as  mere  accessory  helps  to  the  paramount  object 
of  our  labours,  ^^e  have,  indeed,  got  through  the 
almost  herculean  task  of  arranging  the  whole  of  the 
Vertehrata  according  to  their  natural  affinities  and  rela- 
tions, even  down  to  the  sub-genera ;  but  to  follow  up 
this  plan  with  the  annulose  and  the  molluscous  animals, 
would  not  only  swell  the  Cabinet  of  Natural  History  to 
three  times  it  prescribed  limits,  but  would  demand  a 
knowledge  which,  individually,  would  be  superhuman. 
The  great  truths,  or,  rather,  the  leading  one,  which  the 
enlightened  reader  should  have  constantly  brought  before 
him  is,  the  unity  of  plan  in  the  creation  :  this  might 
be  lost  sight  of,  if  the  attention  was  long  withdrawn 
from  such  enlarged  concei>tions,  and  occupied  by  a  mul- 
tiplicity of  small  details,  fit  only  for  the  technical  de- 
scriber  and  the  anatomical  demonstrator. 


CHAP.  I.  PLAN    OF    THE    WORK.  S 

(3.)  Under  all  these  circumstances,  we  must  therefore 
treat  the  molluscous  groups  with  great  brevity  :  the  lead- 
ing divisions,  indeed,  of  the  whole  will  be  briefly  stated, 
sufficient  to  guide  the  researches  of  those  who  may  be 
disposed  to  adopt  our  views  of  natural  arrangement,  and 
to  analyse  their  contents  ;  but  this  will  be  entirely 
subordinate  to  the  primary  intention  of  this  volume, 
which,  it  will  be  seen,  is  almost  exclusively  confined  to 
the  Testacea.  Limited  as  is  our  space,  we  shall 
endeavour  to  fill  it  in  that  way  which  promises  to  be 
of  the  greatest  permanent,  as  well  as  practical,  advantage 
to  science.  The  arrangement  of  one  class  of  the  Mol. 
lusca,  founded  upon  analysis,  is  obviously  more  valu- 
able than  a  theoretical  digest  of  the  w'hole.  We  are 
seeking  to  place  zoology  upon  a  new  basis.  To  discover 
and  develope,  as  far  as  in  us  lies,  the  fundamental  prin- 
ciples of  the  natural  system  ;  and  to  exhibit  its  compo- 
nent parts  —  not  as  detached  portions,  as  if  each  had 
its  own  set  of  laws  and  its  own  little  system  of  arrange- 
ment, but  — as  a  vast  and  connected  whole,  throughout 
which  the  utmost  harmony  and  the  most  perfect  unity 
of  plan  pervades.  To  do  this,  how^ever,  with  any 
degree  of  success,  requires  a  fulness  of  detail,  insepa- 
rably connected  with  the  comprehensiveness  of  the 
subject,  and  the  novelty  of  the  design.  It  is  due,  not 
only  to  the  scientific  public,  but  to  the  labours  of  those 
great  men  whose  opinions  now  reign  paramount,  that 
the  systems  now  in  use  should  not  be  lightly  set 
aside.  Hence  a  variety  of  details,  unnecessary  under 
other  circumstances,  becomes  absolutely  essential  in 
these.  Now,  of  the  three  classes  of  molluscous  animals, 
the  Testacea,  or  shell-fish,  is  that  which  possesses  the 
greatest  degree  of  popular,  and  even  of  scientific,  in- 
terest. Their  beautiful  shelly  habitations  form  some  of 
the  most  interesting  objects  in  our  public  museums 
and  private  collections.  And  although  we  should  not 
consider  ourselves  bound  to  make  this  the  only  reason 
for  a  neglect  of  the  other  classes  of  the  MoUusca,  yet, 
nnder  existing  circumstances,  we  shall  so  far  concede  to 

B    2 


4  SHELLS    AXD    SllKLL-FISH.  PART  I. 

popular  taste^  as  to  devote  our  present  volume  almost 
entirely  to  so  favourite  a  branch.  This  plan  will  enable 
us  to  submit  nearly  the  whole  of  our  investigations  to 
the  public  ;  while  we  trust  to  do  the  same  hereafter  in  re- 
gard to  the  remaining  classes  in  a  separate  publication. 

(4.)  The  innumerable  groups  of  beings  which  we 
comprehend  under  the  general  name  of  Mollusca,  are  at 
once  distinguishable  from  all  other  animals^  by  having  no 
internal  bones^  like  the  Vertehrata  ;  or  no  joints  to  their 
body  and  limbs^  like  the  Annulosa,  or  insect  tribes.  In 
the  first,  the  skeleton  is  internal  ;  in  the  latter,  it  is  ex- 
ternal ;  but,  in  the  Mollusca,  it  is  entirely  wanting. 
We  might  fill  several  pages  on  these  anatomical  dis- 
tinctions ;  but  simplicity  is  the  soul  of  instruction  ;  and 
we  feel  assured,  that  in  following  this  rule,  in  the  pre- 
sent instance,  we  are  saving  the  unscientific  reader  a 
world  of  perplexing  circumlocution. 

(5.)  We  shall  first  glance  at  those  characters  drawn 
from  the  nervous  system,  which,  it  is  thought,  sepa- 
rate the  Mollusca  irora  the  Vertehrata  and  the  Annulosa. 
On  a  former  occasion  *,  we  have  stated  that  their  nerv- 
ous system  is  variable,-  and  that  this  variation  pointed 
out  the  secondary  divisions  or  classes,  under  which  the 
leading  zoologists  of  the  age  have,  almost  unanimously, 
arranged  them.  Thus,  in  the  Acrita,  or  polypes,  the 
nervous  system  has  been  called  granular ;  these  granules, 
innumerable  and  minute,  being  generally  dispersed  over 
the  bodies  of  these  animals,  which  resemble  "  masses  of 
transparent,  homogeneous,  mobile,  and  sensible  pulp, 
and  thus  impregnating  the  whole  with  sensibility ."t   In 

*  Classification  of  Quadrupeds,  p.  37. 

f  Such,  at  least,  is  the  definition  of  the  Acrita  of  MacLeay;  but  our 
recent  researches  among  the  Mollusca  induce  us  strongly  to  doubt  the 
propriety  of  placing  therein  thegreater  part  of  thoseminute  animals  wJiich 
that  celebrated  naturalist  has  arranged  with  the  corals.  Our  present  im- 
pression is,  that  the  whole,  or  nearly  so,  of  the  true  Acrita,  are  com- 
pound zo<)()hytes,  or,  in  other  words,  plant-like  animals;  that  the  Ro. 
tifern  and  Infusoria  are  only  prototypes  of  the  Acrita  in  the  circle  of  the 
lladiatn  ;  and  that  theaimulose  intestinal  worms  are  the  same  among  the 
Annulosa.  As  for  the  Parcncliipnnta,  it  will  be  seen  we  have  had  no 
hesitation  in  placing  them  as  the  representatives  of  this  class  in  the  most 
aberrant  order  of  the  testaceous  Mollusca.  We  feel,  in  short,  more  and 
more  persuaded  that  the  real  contents  of  the  order  Ct/clobrancli/n  cainiot 
be  determined  until  the  entire  class  of  Acrita  has  been  sufficiently  ana- 


CHAP.  I.        PRI3IARY    DIVISIONS    OF    MOLLUSKS.  5 

the  second  class,  or  the  Rauiata,  the  nerves  are  ar- 
ranged in  a  radiated  or  star-  like  manner ;  while  in  the 
testaceous  Mollusca,  or  Testacea,  the  nervous  system 
resides  in  four  ganglions,  either  united  in  pairs,  or 
altogether,  which  are  embraced  by  a  medullary  collar. 

(6.)  It  would  thus  appear  that  the  three  great  divisions 
of  Mollusca  are  as  much  distinguished  by  their  ana- 
tomical peculiarities,  drawn  from  their  nervous  system, 
as  they  are  by  their  external  and  more  obvious  cha- 
racters. It  is  by  these  latter,  however,  that  they  are 
made  intelligible  to  the  generality  of  readers.  Every 
one,  therefore,  will  be  at  no  loss  to  understand  the  ex- 
ternal distinctions  of  these  primary  divisions  :  1.  The 
Testacea,  or  shell  mollusks  ;  2.  The  Raihata,  or 
radiated  mollusks  ;  and,  3.  The  Acrita,  or  polypes. 
The  first  being  represented  by  shell-fish  ;  the  second,  by 
starfish,  sea  eggs,  and  medusas ;  and  the  third,  by  corals, 
polypes,  and  other  plant-like  animals.  We  shall  now, 
in  the  first  place,  point  out  the  manner  of  their  con- 
nection to  the  higher  classes  of  animals,  with  the  object 
of  showing  that  they  form  an  integral  part  of  that  vast 
circle  which  comprehends  the  whole  of  the  animal 
world. 

(7.)  The  primary  distinction  of  vertebrated  animals 
is,  their  being  possessed  both  of  an  internal  column,  or 
back-bone,  and  of  legs  or  other  members  which  give  them 
the  power  of  locomotion  :  it  follows,  therefore,  that  if 
we  found  among  the  soft  Mollusca  any  animals  which 
really  possessed  these  characters,  however  slightly  de- 
veloped, we  should  consider  them  as  forming  the  pas- 
sage from  one  class  to  the  other  ;  that  is,  from  the  Ver- 
tehrata  to  the  Mollusca.  Now,  there  is  a  whole  tribe 
of  animals  which  really  present  us  with  such  a  struc- 
ture, and  yet,  in  all  other  respects,  they  are  so  unlike 
the  Fertehrata,  that  every  writer  places  them  with  the 

lysed.  Between  the  Doridee  and  the  Branchiopoda,  there  must  be,  or  have 
been,  very  many  intervening  forms  :  and  we  begin  to  think  th;it  Ciivier 
may  not  be  very  wrong  in  placing  many,  if  not  all,  of  his  nakiiA  Acephala 
close  to  the  Branchiopoda.  But  the  analysis  of  the  Acrita  can  alone  de- 
termine this  question. 

B    3 


6 


SHELLS    AND    SIIELL-FISH.  PART  I. 


Testacea.     This  tribe  is  the  Cephalopoda,  or  cuttlefiph. 
It  is  among  these  only^  out  of  the  whole  class  of  Mol- 
lusca,  that  we  find  a  distinct,  and  often  rigid,  back-bone, 
— not,  indeed,  jointed  or  articulated,  but  performing  the 
same  office  as  the  vertebrated  column  of  a  quadruped 
or  a  bird :   others  of  its  class  have  no  limbs  whatever  ; 
but  the  cuttlefish  have  immense  arms,  which  are   also 
used  as  legs  ;    by  these  they  crawl  with  the  greatest 
facility  on  the  bottom  of  the  sea,  swim  quickly  in  the 
water,  and  retain  the  most  forcible  hold  of  such  ani- 
mals as  they  prey  upon.     The  eyes  of  nearly  all  Mol- 
lusca   are  either  small  and  indistinct,  or  are  entirely 
wanting ;   in  these,  however,  the  eye  is  large,  and  as 
fully  developed  as  in  any  vertebrated  animal.     There 
cannot,  therefore,  be  the  least  doubt  of  the  close  ap- 
proximation of  the  Cephalopoda  to  the  Vertehrata  ;  and 
as  a  large  proportion  of  the  fossil  species  were  fur- 
nished with  spiral  shells,  it  follows  that  the  testaceous 
class   comes  immediately   after   the    Vertehrata.     This 
affinity  being  established,  we  are  at  no  loss  to  discover 
the  point  of  junction  between  this  and  the  next  class, 
or  the  Jcrita.    The  singular  naked  animals  forming  the 
Nudihranchia    of    Cuvier,    have    been    very    properly 
placed  by  many  authors  close  to  the  tunicated  polypes 
(^Tunicata).      Again,  on  the  other  side  of  the  circle  of 
Acrita,  we  have  the  genus  Zoanthus  and  the  Poli/pes 
charnues  of  the  French  Avriters,  closely  connected  to  the 
Radiata  by  Friapulis  and  other  kindred  forms ;  while 
the  last  vestige  of  the  radiated  structure  is  seen  in  the 
Cirripeda  :   these  latter  animals,  however,  by  their  arti- 
culated limbs,  are  yet  removed  out  of  the  confines  of 
the  Radiata,  although  they  become   the  first  group  in 
the  Annulosa,  —  thus  standing  in  precisely  the  same  re- 
lation as   the  Cephalopoda  do   to  the  Vertehrata.      ^Ve 
have  now  traced  the  chain  of  affinity  into  the  annulose, 
or   insect  class  ;  and  it  only   remains  to  inquire   how 
these  latter  are  connected  to  the  Vertehrata,  or,  in  other 
words,  how  the  animal  circle  is  made  out  and  closed. 
On  this  point,  again,   the  labours  of  our  predecessors 


CHAP.  I.  RANK    OF    THE    TESTACEA.  7 

have  removed  all  difficulty^  and  even  doubt.  The  Anne- 
lides  have  the  joints  of  their  bodies,  like  the  common 
earth-worm,  disposed  in  rings,  but  yet  they  offer  the 
extraordinary  character  of  red  instead  of  white  blood : 
hence^  they  are  always  called  red-blooded  w^orms. 
There  is,  to  be  sure,  no  vestige  of  any  internal  support 
to  the  body,  such  as  we  have  seen  in  the  Cephalopoda  ; 
but  every  one  must  be  struck  with  the  resemblance 
which  exists  between  a  worm  and  an  eel,  —  the  one  being, 
in  form,  almost  the  miniature  of  the  other.  This  re- 
semblance, moreover,  is  carried  much  further  by  certain 
eel-shaped  fishes,  which  are  destitute,  not  only  of  fins, 
but  of  eyes  ;  while  in  others^  as  the  genus  Myxine,  the 
vertebral  column,  or  back-bone,  is  hardly  to  be  dis- 
tinguished. It  is  impossible,  therefore,  for  this  grad- 
ation to  be  more  perfect.  Every  naturalist  of  the 
least  repute  has  viewed  the  connection  of  the  Anne- 
lides  to'  the  fishes  in  this  light ;  and  thus  are  all  the 
classes  of  the  animal  kingdom  united  into  one  vast 
circle. 

(8.)  Of  the  three  divisions  of  the  Mollusca, — namely, 
the  Testacea,  the  Radiata,  and  the  Acrita, —  it  is  obvious 
that  the  latter  are  the  lowest  in  the  scale  of  animal  life; 
the  superiority  of  the  Testacea  to  the  Radiata  must 
also  be  admitted,  when  we  come  to  compare  the  or- 
ganisation of  one  with  the  other.  The  shells  of  the 
Echinid(B,  the  most  typical  group  of  the  radiated  animals, 
are  certainly  as  beautiful  and  complicated  in  their  con- 
struction—  although  not,  perhaps,  in  outward  appear- 
ance —  as  those  of  the  Testacea ;  but  we  must  look  to 
the  animals  themselves.  The  EchinidcE  show  not  the 
least  indication  of  that  form  which  belongs  to  verte- 
brated  animals :  although  provided  with  short  tentacula, 
which  are  supposed  to  assist  them  in  removing  from 
place  to  place,  they  yet  move  so  slowly,  that  a  snail,  in 
comparison,  may  be  said  to  run :  thus  the  Echinus,  al- 
though with  tentacula, — which  are  supposed  to  perform 
the  office  of  feet,  —  can  scarcely  remove  itself  a  few 
inches;  the  snail,  which  has  no  foot  or  similar  processes, 

B   4 


8 


SHELLS    AND    SHELL-FISH.  PART  I. 


crawls  on  its  belly,  at  what,  in  comparison,  is  a  good 
round  pace.  The  typical  Testacea  are  all  provided  with 
eyes,  however  small,  and  with  feelers  ;  but  the  Echinidce 
have  none,  properly  so  called  ;  they  are,  in  fact,  de- 
cidedly lower  in  the  scale  of  creation  than  the  shell- 
fish ;  for,  while  the  whole  of  the  Radiata  are  destitute 
of  eyes,  those  of  the  Testacea,  in  the  pre-eminently 
typical  division  (the  Zoophaga),  and  of  the  Cephalopoda, 
are  generally  very  perfect,  and  always  present.  This 
accords  exactly  with  what,  from  theory,  we  should  have 
supposed  :  that  the  Testacea,  being  nearest  allied  to  the 
typical  Vertehrata,  would  consequently  be  more  perfectly 
organised  ;  while  the  Radiata,  being  cut  off,  as  it  were, 
from  the  Vertehrata,  by  the  intervention  of  the  Arinu' 
losa,  become  further  removed  from  the  great  types  of 
animal  perfection,  and,  consequently,  exhibit  an  inferior 
developement.  The  Testacea  are,  therefore,  the  most 
perfect  of  all  the  Mollusca. 

(9-)  Having  now  indicated,  although  with  more 
brevity  that  we  could  have  wished,  the  relative  station 
of  the  testaceous  Mollusca,  both  in  regard  to  other 
animals  and  their  own  class,  we  shall  direct  our  chief 
attention  to  the  exposition  of  their  natural  and  circular 
arrangement.  Although  we  so  far  concede  to  the  popular 
taste  for  conchology  (as  the  ''  art "  of  arranging  shells 
and  other  testaceous  Ijodies  is  called)  as  to  devote  this 
volume  exclusively  to  the  testaceous  Mollusca,  we  can- 
not sacrifice  our  conviction  on  the  principles  upon  which 
tliese  animals  should  be  studied,  or  fall  into  the  common 
method  now  in  use  of  writing  upon  shells,  independent 
of  all  consideration  for  the  animals  by  which  they  are 
inhabited.  To  dignify  any  pursuit  of  this  kind  by  the 
name  of  Science,  seems  to  us  quite  misplaced ;  since  it 
would  be  hardly  more  absurd  to  classify  birds  by  the 
colour  of  their  eggs,  or  beetles  by  the  shape  of  their 
wings,  than  to  projjound  an  arrangement  of  shells,  with- 
out a  paramount  regard  to  the  animals  which  they 
cover.  It  is  quite  right  that  collectors  of  these  elegant 
objectSj  who  mix  up  with  them  shelly  cases  of  insects 


CHAP.  I.  IIEMARKS    ON    CONCIIOLOGY.  y 

(Cirripedes)  fragments  of  worms  (Annelides),  hack- 
bones  of  cuttlefish^  gill  covers  of  sea  hares  (Aplysia), 
Sec,  should  arrange  them  in  their  cabinets  upon  some 
plan_,  and  give  them  names  ;  but  no  one  will  maintain 
that  this  amusement  deserves  to  be  called  science. 

(10.)  One  of  the  first  zoologists  of  this  country,  in 
speaking  of  the   utter   ignorance  which  exists  on  the 
natural  arrangement   of    the    Testacea,   and  the   high 
importance  that  belongs  to  the  inquiry,   makes  the  fol- 
lowing remarks  :  — "  At  all  events,  it  is  not  to  those 
collectors  who  are  solely  intent  on  the  external  form  of 
a  shell,  or  the  streaks  of  colour  w^hich  ornament  it,  that 
the  hope  of  discovering  the  true  arrangement  of  the  Mol- 
lusca  can  be  held  forth.       The  study  of  shells  appears, 
indeed,  to  be  indispensably  necessary  to  the  geologist ; 
and,  no  doubt,  the  testaceous  covering  of  an  animal  is 
always  so  intimately  connected  with  its  structure,   that 
it  would  be  unpardonable  in   the  naturalist,  who  ought 
to  leave  nothing  without  investigation,  to  forget  shells. 
But,  on  the  other  hand,  when  we  call  to  our  recollection 
the  lamentable   error   committed  by   Linnaeus   and  his 
disciples,  in  not  following  the  example  of  our  celebrated 
Lister  in  the  arrangement  of   the    Mollusca,  we    be- 
come convinced  there  was  about  as  much  hope  of  their 
ever  arriving  at  the  truth  by  the  means   they  chose  to 
adopt,  as  that  a  collection  of  the  wings  of  different  in- 
sects should  ever  instruct  us  fully  in  the  natural  history 
of  the  animals  to  which   they  belong.      It  is   said  that 
Klein  formed  an  ornithological  cabinet,  in  which  the 
feet  and  beaks  of  birds  were  only  to  be  seen ;  because, 
according  to  his   notions,    they  were   all  the  parts  re- 
quisite for  the  proper   arrangement   of   the   feathered 
creation.     He  thought  that  it  was  possible  to  be  a  good 
ornithologist,  without  knowing  the  least  of  a  bird  but  its 
beak  and  claw.     We  may,  indeed,  laugh  at  this ;   but, 
at  the  same  time,  we  ought  to  inquire  whether  similar 
ridicule  may  not,  with  justice,   be   extended   to  those 
conchologists,  who,  having  procured  a  shell,  describe  and 
classify  it  without  deigning  to  bestow  a  single  thought 


10  SHELLS    AND    SHELL-FISH.  PART  J. 

on  the  nature  of  the  poor  animal  which  constructed  it 
for  its  habitation.*  A  curious  arrangement,  as  might 
have  been  expected,  has  come  of  this  method  of  pro- 
ceeding;  for  we  have  annulose  animals  i'  (or  insects) 
united  to  true  Mollusca,  merely  because  they  have  shells; 
and  true  Mollusca  separated  from  this  division,  merely 
because  they  have  no  shells.  In  some  cases,  even,  as  in 
the  genus  Limax,  it  is  sufficient  for  the  shell  to  be 
small,  in  order  to  set  it  wide  asunder  from  animals  of 
the  same  family  :  but  it  would  be  endless,  as  well  as 
useless,  to  detail  the  violations  of  natural  order  mani- 
fested by  Linnaeus  in  his  systematic  arrangement  of  the 
mollusks,  which  have  so  truly  constituted  .his  stum- 
bling block.  It  cannot,  however,  be  denied,  that,  could 
we  adopt  his  notion  as  to  the  nature  of  the  animals,  the 
principles  upon  which  he  arranged  their  testaceous  co- 
verings are  excellent.  To  those  who  admire  the  splen- 
dour of  the  pencilling,  the  beauty  of  the  enamel,  and 
the  variety  of  sculpture,  which  exist  in  shells,  it  might 
be  depriving  them  of  an  innocent  amusement,  to  object 
the  trivial  nature  of  their  study  as  leading  to  no  general 
results ;  but  it  may  be  as  well  to  remind  them,  that, 
unless  they  add  to  their  satisfaction  and  to  their  know- 
ledge by  studying  the  structure  of  the  animals  them- 
selves, there  is  no  more  science  in  the  disposition  of 
their  cabinets,  than  may  appear  in  the  tasteful  arrange- 


*  A  modern  compiler,  who  has  been  at  some  pains  to  draw  up  what  he 
considers  some  general  observations  on  the  "  Principles  of  Conchology," 
very  properly  refrains  from  bestowing  upon  it  the  name  of  a  science. 
"  Conchology,"  as  he  observes,  "  is  the  art  of  arranging  the  protecting 
bodies  of  testaceous  "  (and  he  might  have  added  of  annulose)  "  animals, 
so  as  to  enal)le  us  to  recognise  them  promptly  and  certainly,  without  giving 
any  attention  to  the  animals  which  they  have  contained,  or  contain,  or,  at 
least,  regarding  this  part  a<  a  matter  of  very  minor  imiiortaiice."  Inde- 
pendent of  the  assistance  this  ''  art  "  bestows  to  the  studies  of  the  geologist, 
he  further  observes,  "  it  may  almost  be  regarded  as  a  study  nearly  idle  and 
useless  by  all  true  zoologists."  Nay,  he  continues,  "it  is  really  to  this 
cause  that  conchology,  properly  so  called,  owes  both  the  continuance  of  its 
existence,  and  the  daily  increasing  efforts  of  enlightened  naturalists,  who 
endeavour  to  give  it  sure  priMcii)les  and  rules."  He  omits  to  inform  us, 
however,  how  these  sure  principles  and  rules  can  be  attained  in  an  "  art  " 
which  absolutely  rejects  that  solid  foundation  for  them,  upon  which  their 
true  knowledge  depends,  —  that  is,  a  primary  regard  to  the  principles  of  the 
variation  in  these  animals. 

f  The  CirripedeSy  or  barnacles. 


CHAP.  I.  REMARKS    ON    CONCIIOLOGY.  11 

ment  of  porcelain  on  a  mantelpiece.  Separate  the  shell 
from  the  animal,  and  much  less  acquaintance  with  the 
natural  system  is  to  he  derived  from  their  inorganic 
covering,  than  Klein  obtained  of  his  birds_,  by  seeing  only 
their  beaks  and  claws."  * 

(11.)  The  above  sentiments  on  the  insufficiency  of 
the  shell,  in  all  cases,  to  determine  its  place  in  the 
natural  system,  we  are  free  to  confess,  were  held  by 
us  for  many  years.  But  the  results  of  that  analysis 
now  given  to  the  public,  have  materially  modified,  if 
not  altered,  this  opinion.  It  is  needless,  perhaps,  to 
repeat,  that  a  primary  regard  must  always  be  had  to 
the  nature  of  the  mollusk  itself ;  and  that,  without  this 
knowledge,  there  are  certain  forms  of  Testacea,  of 
which  neither  their  natural  tribes  nor  families  can  be 
conjectured,  and  which,  for  this  reason,  should  always 
be  kept  apart.  There  are  others,  again,  belonging 
to  totally  different  families,  or  even  orders,  which 
are  so  alike  in  their  shells,  that  conchologists  place 
them  in  juxta-position.f  But  yet,  on  the  other 
hand,  there  are  numerous  other  families,  where  the 
modifications  in  the  form  of  the  shell  are  just  as  im- 
portant, and  even  more  so,  than  those  of  the  animal. 
The  molluscous  system  of  Poll  fully  establishes  this 
proposition,  even  though  the  innumerable  proofs  in  its 
support,  hereafter  detailed,  were  rejected.  The  truth 
appears  to  be,  that  Nature,  on  the  whole,  has  diversified 
the  external  aspect  of  these  singular  animals,  —  that  is, 
their  shells, — much  more  than  she  has  their  soft  or  more 
unsightly  parts.  If,  therefore,  she  has  thus  bestowed 
all  her  beautiful  embellishment  upon  the  habitation 
rather  than  upon  the  inhabitant,  we  may  at  least  con- 
clude that  the  one  is  as  essential  to  develope  the  plan 
she  has  pursued  in  her  own  system,  as  is  the  other. 
The  diversity  she  has  created  on  the  shelly  coverings  of 
the  typical  Testacea  is,  beyond  all  comparison,  greater 

*  Hor.  Entom.  p  240—244. 

f  Particularly  the  prototypes  of  the  Planariilar,  as    Vitrina,  Sigarelus,, 
Chcelinotus,  &c. 


12  SHELLS    AND    SHELL-FISII.  PART  I. 

than  is  to  be  found  among  their  animals ;  but  these 
latter  must  be  well  studied,  before  we  can  comprehend 
the  leading  types  of  form  prevalent  among  the  former. 
When  this  last  discovery,  if  only  in  part,  has  been 
made,  we  shall  find  that  the  slightest  modification  in 
the  shell  is  not  without  its  meaning;  and  that,  in  nine 
instances  out  of  ten,  we  may  pronounce  with  as  much 
confidence  on  its  natural  station  in  the  scale  of  nature, 
as  if  we  had  actually  dissected  its  animal. 

(12.)  A  singular  idea  appears  to  be  entertained  by 
some  writers,  that  the  "^art"  of  conchology,  popularly 
so  called,  is  only  really  serviceable  to  science,  when 
viewed  in  connection  with  geology.  But  it  may 
fairly  be  asked,  how  geology  or  any  other  branch  of 
knowledge  can  be  benefited  by  any  aid  which  is  not,  in 
itself,  built  on  sound  and  philosophic  principles,  which 
this  '^'^art"  confessedly  is  not.  It  would  be  difficult  to 
answer  the  question  why  one  branch  of  zoology  is  to  be 
separated  from  the  others,  and  degraded  into  the  hand- 
maiden of  another  science, — and  that,  too,  of  such  very 
recent  formation,  that  the  most  opposite  opinions  as  to 
its  very  first  principles  are  continually  issuing  from  the 
press.  It  is  not  a  little  singular,  also,  that,  while 
geologists  appear  to  attach  so  much  importance  to 
mineral  conchology,  as  it  is  termed,  no  author,  as  yet, 
has  specifically  written  on  the  subject.  In  such  a  state 
of  things,  the  attempts  that  are  made  to  identify  certain 
strata  by  the  nature  of  the  shells  they  may  contain,  should 
be  ventured  upon,  in  most  cases,  with  very  great  cau- 
tion. We  are  fully  persuaded  that  many  of  those  fossil 
shells  termed  by  conchologists  fluviatile,  are  decidedly 
marine  ;  that  the  nature  of  others,  from  ignorance  of 
their  animals,  can  never  be  understood ;  and  that  a 
great  number,  now  considered  identical  with  existing 
genera,  belong  to  groups  altogether  extinct.  Until, 
therefore,  all  these  suspicious  points  are  cleared  u}), 
geologists  will  derive  but  very  little  comparative  benefit 
by  our  modern  systems  of  conchology,  and  will  be  fre- 
quently led  to  most  erroneous  conclusions.    The  "  art," 


CHAP.  I.  BIBLIOGRAPHY    OF    MALACOLOGY.  13 

in  fact^  must  merge  into  the  science  of  Malacology, 
in  which  equal  regard  is  paid  both  to  the  animal  and 
the  shell.  It  is  then  alone  that  geology  will  be  really 
benefited.  Our  science  will  then  repose  upon  a  proper 
and  philosophic  basis^  and  in  that  capacity  will  be  ready 
to  aid  those  of  her  sisters  who  may  solicit  her  services. 
(13.)  Our  notices  on  the  Bibliography  of  the  tes- 
taceous Mollusca,  must  be  very  brief,  and  chiefly  con- 
fined to  such  as  have  a  practical  influence  on  the  present 
state  of  science.  This  brevity  will  be  the  less  regretted, 
since  the  subject  has  been  so  ably  and  fully  gone 
into  by  Maton  and  Racket,  in  the  seventh  volume  of  the 
Linncean  Transactions.  The  foundation  of  this  and 
every  branch  of  zoological  science  was  laid  by  the  im- 
mortal Aristotle,  who  well  discriminated  all  the  leading 
groups  of  the  typical  Testacea,  and  was  not  inattentive 
to  the  habits  and  localities  of  the  animal  inhabitants. 
He  separated  the  spiral  univalves  by  the  name  of  Mo- 
nothyra,  while  he  applied  the  term  of  Dithyra  to  the  bi- 
valves. It  would  have  been  as  well  if  the  moderns,  in 
their  multifarious  and  complicated  nomenclature,  had 
shown  some  little  respect  to  the  designations  imposed  by 
this  commanding  genius  on  the  leading  groups  of  Xhe  Mol- 
lusca ;  such  defence  would,  at  all  events,  have  brought 
his  name  more  frequently  before  us,  and  reminded  the 
world  how  infinitely  science  was  indebted  to  his  labours. 
How  much  superior,  also,  is  the  simplicity  of  genuine 
classic  names  over  those  compounded  in  modern  times, 
will  be  best  seen  by  comparing  those  bestowed  upon 
the  bivalves,  which  are  the  Dithyra  of  Aristotle,  and 
the  Malacozoaria  Acephalophora  of  M.  de  Blainville. 
It  is  too  late,  perhaps,  to  restore  the  entire  nomen- 
clature of  the  illustrious  Stagyrite  ;  but  in  this  single 
instance  we  shall  certainly  prefer  his  designation  of  the 
bivalve  Mollusca  in  preference  to  those  of  the  moderns.* 

*  The  term  of  Acephcila,  given  by  Cuvier,  would  be  by  no  means  objec- 
tionable, but  that  it  sets  aside  the  name  of  antiquity,  and  include?,  more- 
over, numerous  groups  which  have  nothing  in  common  with  the  Dithyra 
of  Aristotle,  except  the  want  of  a  distinct  head.  To  judge,  indeed,  from 
the  writings  and  nomenclature  of  the  French  school,  it  would  hardly  be 
conjectured  that  such  a  man  as  Aristotle  had  ever  existed. 


14j  shells  and  shell-fish.  part  1. 

(14.)  Our  celebrated  countryman.  Lister  *,  was  the 
first  naturalist,  after  the  revival  of  learning,  who  made 
any  decided  improvement  in  this  science,  since  he  re- 
garded both  the  animals  and  the  shells  ;  and  his  noble 
volume  will  be  an  imperishable  record,  both  of  his 
talents  and  his  industry.  The  excellent  figures  of 
Rumphiust;,  published  in  1711:>  are  still  valuable,  as 
are  likewise  those  of  Gualtieri  :|:,  but  neither  of  these 
writers  can  scarcely  be  said  to  have  benefited  the  subject 
in  any  other  way.  D'Argenville's  plates,  although  more 
elaborately  finished,  are  very  inferior  to  those  of  the 
last-named  works  ;  and  it  has  been  truly  said,  that  what 
is  really  valuable  in  his  book  has  been  taken  from 
Lister.  The  conchological  labours  of  Klein,  who  was 
perpetually  writing  upon  every  branch  of  natural  his- 
tory, partake  of  the  character  which  belongs  to  all,  —  a 
total  want  of  genius.  It  was,  in  fact,  reserved  for 
Adanson§,  the  celebrated  French  traveller  and  naturalist, 
once  more  to  revive  malacology  from  the  frivolous  state 
into  which  it  had  been  gradually  sinking  since  the  days 
of  Lister  :  by  studying  both  the  animal  and  its  shell, 
he  prosecuted  his  researches  on  sound  and  philosophic 
principles ;  and  hence  it  is,  that  his  volume,  although 
published  in  1757:,  is  highly  valuable,  while  the  '^  tes- 
taceous "  arrangement  of  Linnaeus  is  as  if  it  had  never 
been  written,  —  or  it  is  consulted  only,  at  rare  intervals, 
to  determine  a  specific  name.  But  Adanson  confined 
himself  to  the  shell-fish  of  Senegal ;  and  it  was  not  sur- 
prising that  the  scientific  world,  captivated  by  the  sim- 
plicity of  the  Linngean  nomenclature,  still  continued 
attached  to  the  plan  of  considering  the  Testacea  merely 
in  regard  to  their  shells,  of  which  innumerable  species 
now  began  to  pour  in  on  the  European  cabinets.    This, 

*  Lister.  Historia,  sive  Synopsis  Metliodica  Conchyliorum.  London, 
one  volume,  folio  ;  of  which  there  are  two  editions,  the  last  in  two  volumes. 
See  Prcl.  Discourse,  p.  24. 

t  Ku.MPHius,  G.  E.  'J'hesaurus  Imaginum  Piscium,  Testaceoriim,  &c. 
Haga;  Comilum,  17;)9,  folio. 

:  Nico.  GuALTiiRi.  Index  Testatum  Conchyliorum.  Flor.  1742,  royal 
folio.  The  figures  are  the  most  artisticai  of  any  that  we  remember:  the 
rotundity  of  the  spiral  shells  is  admirably  represented. 

\  Hist.  Nat.  des  Coquillages  du  Senegal.    Tans,  1757,  4to. 


CHAP.  I.  BIBLIOGRAPHY    OF    MALACOLOGY.  15 

doubtless,  gave  rise  to  the  voluminous  work  of  Martini 
and  Chemnitz,  which,  although  published  between 
1769  and  1788,  and  with  figures  exceedingly  ill  drawn, 
is,  nevertheless,  the  most  valuable,  as  a  general  work, 
we  yet  possess.  It  was  soon  after  this  time,  however, 
that  George  Humphrey*,  F.L.S.,  the  chief  commercial 
conchologist  then  living,  gave  to  the  w-orld  a  small 
pamphlet,  wherein  he  arranged  the  Testacea  upon  an 
entirely  novel  and  very  remarkable  plan.  As  a  system 
of  conchology,  this  w^as  both  a  sudden  and  a  most 
extensive  improvement  upon  everything  of  the  kind 
which  had  hitherto  been  done.  The  arrangement, 
which  wdll  be  subsequently  adverted  to^  as  far  excels 
that  of  Linnaeus,  as  Lister's  exceeds  that  of  Klein. 
There  can  be  no  doubt,  in  fact,  that  this  little  unpre- 
tending pamphlet,  published  in  this  country  merely 
as  an  exhibition  catalogue^  found  its  way  to  France,  and 
served  as  the  main  foundation,  although  unacknow- 
ledged, for  the  subsequent  system  of  Bruguiere,  if  not 
of  Lamarck  and  Cuvier.  It  was,  to  write  colloquially_, 
the  first  quiet  but  thorough  breaking  of  the  ice,  in 
which  conchologists  were  bound  up  by  the  Linnfean 
system  ;  and  those  w^ho  followed  up  the  reformation, 
however  justly  we  may  praise  them  as  improvers,  can- 
not be  invested  with  the  more  honourable  distinction 
of  leaders.  It  was,  therefore,  not  in  France,  but  in 
England,  that  the  revolution  against  the  meagre  concho- 
logical  school  of  Linnaus  first  originated.  But,  having 
said  this,  w^e  can  put  forth  no  claims  for  our  countrymen_, 
on  this  head,  during  a  subsequent  period  of  nearly  forty 
years.  Montagu,  indeed,  must  be  named  with  honour, 
and  Pennant's  writings  aided  much  to  spread  a  taste  for 
collecting  shells  ;  but  beyond  these,  we  recollect  no  others 
deserving  special  record.  Meantime,  a  more  correct 
knowledge  of  the  molluscous  animals  was  making  rapid 
progress  on  the  Continent.  Those  illustrious  and  ad- 
mirable anatomists.  Poll  in  Italy,  and  Cuvier  in  France^ 

*  Museum  Calonnianum.  —  Specification  of  the  variouo  Articles  which 
compose  the  magnificent  Museum  of  Natural  History,  collected  by  M.  de 
Calonne  in  France.     Anonymous.    London,  May  1.  1797. 


10  SHELLS    AND    SHELL-FISH.  PART  I. 

were  prosecuting  their  researches  with  indefatigable 
industry  ;  while  Bruguiere,  and  subsequently  Lamarck, 
were  no  less  occupied  in  describing  and  arranging  the 
Testacea;  meantime^  faint  attempts,  in  the  shape  of  In- 
troductionSj  to  keep  alive  Linnaean  conchology,  were  all 
that  appeared  in  England  on  this  subject.  The  labours 
of  Bruguiere  were  unfortunately  terminated  prematurely 
by  deaths  but  those  of  his  illustrious  friend  Lamarck 
were  continued  up  to  within  these  few  years.  His 
masterly  and  incomparable  work,  wherein  aU  his  labours 
on  the  invertebrated  animals  are  concentrated,  are  too 
well  known  to  be  expatiated  upon  in  this  place,  since  it 
is  in  the  hands,  or  should  be,  of  almost  every  zoologist 
who  studies  those  classes.  The  investigations  of  Poli, 
even  more  elaborate  than  those  of  Cuvier,  have  been 
given  to  the  world  more  slowly,  and  in  such  an  expen- 
sive form,  as  to  deprive  them  of  half  their  utility.* 
Not  so  with  those  of  the  celebrated  Cuvier.  The 
Regne  Animal,  a  book  accessible  to  all  purchasers,  con- 
tains the  essence  of  all  his  labours  on  the  Mollusca, 
but,  unfortunately,  so  much  abridged,  that  the  student 
is  frequently  more  perplexed,  than  satisfied,  on  the 
point  he  is  searching  for.  His  more  detailed  memoirs 
are  scattered  through  innumerable  volumes  of  foreign 
transactions,  where  they  lie  completely  hidden  from 
every-day  reference,  although  their  intrinsic  and  per- 
manent value  would  fully  warrant  their  being  collected 
and  printed  in  a  cheap  volume.f  In  estimating  the 
merits  of  these  three  great  men,  —  Poli,  Cuvier,  and  La- 
marck,— in  regard  to  their  arrangement  of  the  testaceous 
Mollusca,  it  may  be  stated,  that  the  first  confined  his 
system  entirely  to  the  animal,  giving  to  it  a  difi^erent 
name  to  that  of  the  shell ;  so  that,  if  the  animals  of  two 
conchological  genera  (as  Avicula  and  Lima^  were  nearly 

*  Poll  Testacea  Utriusque  Sicilia',  eorumque  Historia  et  Anatomia, 
2  vols,  royal  folio.    Parma',  1790 — 5. 

A  Supplement,  by  Stephaiius  della  Chiaje,  forming  another  volume, 
was  published  at  Naples  in  1S.')3. 

f  A  few  copies  of  these  3/e?«o»rs,  with  their  plates,  were  struck  ofT  se- 
parately, and  published  in  one  4to.  volume,  Paris,  1817  ;  but  this  is  now 
become  so  rare  as  to  be  unprocurable,  excepting  hy  chance. 


CHAP.  I.  RECENT    WORKS.  17 

alike,  they  were  placed,  in  his  system,  in  one  and  the 
same  genus.  Cuvier  has  altogether  avoided  this  strange 
mode  of  procedure  ;  but  an  inspection  of  his  system 
will  bear  us  out,  we  think,  in  our  opinion  that  he  has 
placed  far  too  great  a  stress  on  the  modes  of  respiration, 
and  paid  too  little  attention  to  the  shell,  no  less  than  to 
the  animal ;  while  the  great  error  of  Lamarck  appears  to 
have  been  that  of  giving  to  the  shell,  and  more  espe- 
cially the  hinge  of  bivalves,  a  greater  regard  than  he 
bestows  upon  the  animal.  The  system  of  M.  de  Blain- 
ville,  indeed,  professes  to  remedy  these  defects  ;  but  we 
can  discern  in  it  little  that  is  new,  beyond  innumerable 
compound  Greek  names,  proposed  for  groups  already 
established  by  his  predecessors,  and  which  are  only 
calculated  to  overturn  all  existing  nomenclature,  with- 
out adding  anything  practical  to  the  advance  of  science. 
(15.)  Whatever  may  be  the  cause,  certain  it  is  that 
nearly  all  that  is  now  valuable  in  malacology  has 
emanated  from  the  Continental  naturalists.  Besides 
those  just  enumerated,  the  unwearied  zeal  of  the  French 
circumnavigating  naturalists,,  more  especially  M.  Quoy, 
has  added  to  this  science  not  merely  a  host  of  new 
shells,  but  —  what  is  far  more  valuable  —  innumerable 
facts,  of  the  highest  importance,  regarding  their  animals. 
We  only  regret  that  the  price  of  these  splendid  publica- 
tions, and  the  few  copies  of  them  yet  in  this  country,  have 
prevented  us,  in  all  instances,  from  profiting  from  these 
most  valuable  materials.  The  only  one  of  our  country- 
men who  has  pursued  the  same  path  of  inquiry,  and 
on  the  same  philosophic  principles,  was  our  late  friend, 
the  Reverend  Lansdown  Guilding,  who,  from  his 
official  residence  in  the  West  Indies,  had  the  enviable 
opportunity  of  examining,  and  the  rarely  united  talents 
of  drawing,  dissecting,  and  describing,  the  soft  MoUusca 
of  the  Caribbean  seas.  To  him  is  science  indebted  for 
a  knowledge  of  the  animals  of  numerous  terrestrial  and 
many  marine  shells  ;  and  the  institution,  on  the  most 
solid  basis,  of  several  natural  genera.  These  invaluable 
researches,  too  little  appreciated  by  our  conchologists, 

G 


18  SHELLS    AND    SHELL-FISII.  PART  I. 

in  their  zeal  for  describing  new  species,  and  too  little 
known  to  the  scientific  world,  from  being  scattered  in 
detached  papers,  or  unpublished,  are  all  incorporated 
and  acknowledged   in  this  volume.*     To  this  accom- 
plished zoologist  and  exquisite  artist  are  we  indebted, 
among  many   other   things,   for   the  discovery   of   the 
extraordinary    genus    Herpa ;     and    for    drawings    of 
the  animals  of    Oliva,    Volutella,   Marginella,    Triton, 
and  Trochella;  as  also  of  several  other  groups,  originally 
characterised  from  the  shells  alone,  but  now  confinued 
by    the    difference    of    their    animals.     The    name    of 
Mr.  Lowe,  the  natural  historian  of  Madeira,  deserves 
honourable  mention  in  this  place,   as   connected  with 
the  illustration  of  many  interesting  facts  on  the  Mollusca 
of  that  island.     A  most  magnificent,  but  extravagantly 
expensive,  work  on  the  land  and  freshwater  shells,  was 
commenced,   several   years   ago,   by   the  late  baron  de 
Ferussac.t    As  it  was  patronised  by  Royalty,  some  hopes 
were  entertained  of  its  completion,  notwithstanding  the 
grand  scale  it  set  out  upon  ;  but  the  undertaking  was 
evidently  too  vast  for  the  very  moderate  abilities  of  its 
projector ;  the  parts  came  out  less  and  less  regularly, 
until,  after  it  had  cost    the  subscribers   near   50/.,   it 
was  (virtually)  given  up,  and  the  author  died.     This 
striking  example  is  surely  sufficient   to  convince  any 
sober  judging  person  of  the  utter  impracticability  of 
completing   a  General    Conchology,  or   of  carrying  it 
on  beyond  a  few  numbers.     It  is,  in  fact,  a  physical 
impossibility  for  any  one  or  five  men  to   accomplish 
such  a  work  in  the  ordinary  term  of  human  life ;  and 
even  if  brought  to  a  termination,  unless  conducted  on 
the  most  economic  scale,  would  involve  an  outlay  to 
the  projectors,  and  an  expense  to   the  public,    which 
the   latter,   at  least,  would   never  incur.     We  are,   in 
truth,  heartily  set  against  all  these  magnificent  under- 
takings :    they  are   absolutely  detrimental   to   science ; 

*  A  large  collection  of  highly  finished  drawings,  and  several  MSS.,  are 
now  in  the  possession  of  Mr.  Guilding's  late  widow. 

t  I'ERUssAc  Hist.  Nat.  gC'ntralc  et  particulierc  dcs  MoUusques  Ter- 
restres  et  Fluviatiles,  27  parts,  published,  Paris,  1819 — 3J. 


CHAP.  I.  SYSTEMS    AND    ARRANGEMENTS.  I9 

for  they  confine  the  materials  of  knowledge  and  of 
study  within  the  narrow  limits  of  the  select  few  (gene- 
rally wealthy  amateurs)^  to  the  exclusion  of  all  who 
cannot  expend  400/.  or  500/.  upon  a  zoological  library. 
We  cannot  but  admire  the  zeal  of  their  projectors_,  — 
for  such  works  never  produce  profit,  and  generally  bring 
a  heavy  loss, — but  we  think  it  a  zeal  misplaced.  What 
is  now  most  wanted,  is  a  collection  of  plates  of  shells, 
to  supply  the  deficiencies  of  the  series  in  the  Tableau 
Encyclopedique  et  Metliodique  *,  and  printed  uniformly. 
The  series  in  question  contains  nearly  300  plates,  and 
is  the  very  best  which  the  naturalist  can  possess.  We 
have  constantly  referred  to  it,  as  being  more  within  the 
pecuniary  reach  of  the  student,  and  as  being  far  more 
accurate  in  the  figures,  although  uncoloured,  than  that 
of  Martini  and  Chemnitz  ;  and  these  latter  are  there- 
fore only  quoted  for  species  not  contained  in  the  other. 
The  figures  in  Wood's  Catalogue  are  often  very  good  ; 
but  the  arrangement  is  so  confused,  and  often  so  erro- 
neous, that  the  nomenclature,  in  its  present  state,  can 
seldom  be  quoted  as  an  authority. 

(l6.)  In  regard  to  systems  and  arrangejients  of 
the  testaceous  animals,  the  only  attempt  that  has  ever 
yet  been  made  towards  the  natural  disposition  of  this 
extensive  class,  is  that  indicated  in  the  Horce  Ento- 
mologies. The  ingenious  author,  however,  candidly 
acknowledges  his  inability  even  to  point  out  the  primary 
divisions;  although  he  has  ventured,  and,  as  we  think, 
has  partially  succeeded,  in  tracing  the  links  of  affinity 
by  which  the  testaceous  Mollusca  are  connected,  on  one 
side,  to  the  Aerita,  or  polypes,  and,  on  the  other,  to 
the  vertebrated  animals,  by  means  of  the  Cephalopoda. 
Of  arrangements  made  without  any  ulterior  object  of 
illustrating  the  general  harmonies  of  nature,  and  there- 
fore artificial  t,  there  are  several ;  the  best  being  those 

*  With  these  plates,  and  Lamarck's  volumes  of  the  Hist.  Nat.  des  Ant- 
maux  sans  Vertibres,  the  conchologist  will  be  at  no  loss  to  arrange  an 
ordinary  collection  of  shells,  and  name  by  far  the  greater  portion  of  the 
species.  The  excellent  Manuel  de  I'Hist.  Nat.  des  Moliusques  of  M.  Sander 
Rang  should  also  be  procured,  on  account  of  the  valuable  notices  it  con- 
tains on  the  structure  of  the  animals. 

t  See  Geography  and  Classification  of  Animals,  p.  125. 

c  2 


20 


SHELLS    AND    SHELL-FISH. 


PART  I. 


of  Humphrey,   Lamarck,  and  Cuvier.     The  two  first 
of  these  will  therefore  be   exhibited   in  their  details  ; 
the  latter  having  already  been  placed  before  the  reader 
in  a  former  volume.     Although  that  of  Lamarck,  by 
common  consent,  has  been  preferred  by  nearly  all  zoo- 
logists, it  is  but  justice  to  the  distinguished  author  of 
the  Regne  Animal,  to   designate    his    early   Memoires 
upon  these  animals  as  fully  entitling  him  to  the  high 
reputation  his  anatomical  talents  have  so  justly  acquired 
for  him  in  other  departments.    They  are  materials  upon 
which  all  true  knowledge  of  the  Testacea  must  repose. 
(17-)  The  conchological  arrangement  of  Humphrey, 
already  spoken  of,  will  now  be  detailed,  so  far,  at  least, 
as  regards  the  names  of  the  genera  ;  since  their  de- 
finitions were  never  published.  To  show  how  intimately 
very  many  of  these  accord  with  those  of  Lamarck,  we 
have,  in  almost  every  instance,  added  the  corresponding 
genus  of  the  latter.     The  ingenious  author  had  such  a 
conviction  that  the  fluviatileand  terrestrial  genera  should 
be  kept  distinct  from  the   marine,  that  he  places  them 
in  separate  divisions.* 

Class  TESTACEA. 
Order  I.    MARINE. 


Division 

I.  Univalves. 

Conus  L. 

Serpula  Linn. 

Melo. 

Broderip. 

Dentalium  L. 

Valuta  L. 

Patella  L. 

Musica. 

Voluta  Lam. 

Larva. 

Fissurella  Lam. 

Harpa. 

La  771. 

Crypta. 

Crepidula  Lain. 

Dolium. 

La7n. 

Calyptra. 

Idem  Lam. 

Casida. 

Lam. 

Galerus. 

Calyptrffia  Lam. 

Haliotis  L. 

Pedum. 

Spirula  Lant. 

Haliotoidea. 

Stomatia  Lam. 

Nautilus  L. 

Auris  Veneris. 

Sigaretus  Lam. 

Argonauta  L. 
Bulla  L. 

Neritoidea. 

i;  lanthina,  &c. 
(.     Lam.         • 

Licium. 

Ovula  Lam. 

Uber.         ; 
Lunatus.  ',\ 

Natica  Lam. 

Cypraea  L. 

Dactylus. 

Marginella  Lam. 

Nerita  L. 

Oliva  L. 

Auris  Mustela;. 

Tornatella  La7H. 

*  The  author,  with  that  modesty  which  was  his  peculiar  characteristic, 
thus  expresses  himself:  —  "  I'he  editor  hopes  that  his  confession  of  being 
but  little  acquainted  with  the  learned  languages  will  be  received  as  an 
apology  for  such  improprieties  in  the  generic  orspecific  names  as  he  fears 
will  be  found."—  Museum  Calon/ieanum,  pref.  p.  v. 


CfHAP.  I. 

SYSTEM    OF    HUMPHREY. 

21 

Turbo  L. 

Strombus. 

Pterocera.  Lam. 

Eutropia. 

PhasianellaLflw. 

Triplex.    '  > 
Purpura..' 

Scala. 

Scalaria  Lam. 

Mtirex  Lmn. 

Terebra. 

Lam. 

Rheda. 

Hyalia  Lam. 

Obeliscus. 

Trochus  Linn. 

Cochlus. 

■  Cidaris  Sw. 
I  Marmarostoma. 

Div.  IL 

Bivalves. 

Pinna  L. 

€enectus. 

SV3. 

Mytilus  L. 

Blench  us. 

Sw. 

Solen  L, 

Physeter. 

Solarium  Lam. 

Margaritifera. 

Avicula  Lam, 

Apiculum. 

Trochus  Lam. 

Vulsella. 

Lam. 

Trochulus.  7 
Trochus-    3 

Placuna. 

Lam. 

Monodon  Lam. 

^     M  «-•  ^.z  v«  ■  m  b4  ^ 

Cepa. 

Anomia  Linn. 

Sol. 

Tubicanthus  Sw. 

Lampus. 

Terebratula  Lam 

Onustus. 

Sw. 

Mactra  L.  7 
Trigonella.3 

PygmEea. 

Columbella  Lam. 

Mactra  Linn, 

Pyrum. 

Pyrula  Lam. 

Tellina  L. 

Haustrum. 

Purpura  Lam. 

Cuneus. 

Donax  Linn. 

Hystrlx. 

Ricinula  Lam. 

Pectunculus. 

Venus  Linn. 

Bulbus. 

Rapella  Stv. 

Cardium  L. 

Acus. 

Terebra  Lam. 

Trapezium. 

Chama  Lhtn. 

Clava. 

Cerithium  Lam. 

Tridacna. 

Lam. 

Cassidula. ' ' 
Ficus. 

Pyrula  Lam. 

Glycymeris. 
Area  L. 

Lam. 

Rhombus. 

Fusus,  &c.  Lam. 

Pecten. 

Lam. 

Rana. 

Ranella  Lam. 

Ostrea  L. 

Buccinum. 

Triton,  &c.  Lam. 

Lacinia. 

Chama  Lam, 

Turris. 

Turritella  Lam. 

Spondylus  L. 

Colus.  7 
Fusus.  3 

Fusus  Lam. 

Div.  III.  MuLTivALVEs. 

Cuma. 

'Fusus  Lam. 
( .  Fasciolaria  lb. 

Pholas  L. 

Lepas  L. 

Mitra. 

Lam. 

Cornucopia. 

Lepas  Linn. 

Murex. 

Scolymus  Sw. 

Balanus. 

Rapum. 

Turbinella  La7n. 

Chiton  L. 

Alatus. 

Strombus  Linn. 

Order  II.     FLUVIATILE. 


Div.  T. 

Univalves. 

Div. 

II. 

Bivalves. 

Catillus.    ■ 
Neritella. , 

Barbata. 

Unio  Lam. 

Neritella  Lam. 

Scapha. 

Iridina?  Lam. 

Pomus. 

Ampullaria  Lam,. 

Mya. 

Unio  Lam. 

Vesica. 

'Lymnia. 
'.  Melania  Lam. 

Nux. 
Capsa. 

Cyclas  Lam. 

? 

Ligula.       7 
Turricula.  3 

Melania  Lam. 

Order  IIL    T 

ERRESTRIAL. 

Sylvicola. 

Cyclostoma  Lam. 

Otis. 

Auricula  Lam 

Helix  L. 

Chersina. 

Achatina  Lam 

Lituus. 
Cistula. 

Cyclostoma?Za7«. 
Cyclostoma. 

Lendix. ' 
Pupa.     J' 

Pupa  Lam. 

,Bombyx. 

? 

22 


SHELLS    AND    SHELL-FISH.  PARTI. 


(18.)  As  a  purely  conchological  system,  this  was  un- 
questionably the  best  and  the  most  original  of  any  that 
had  appeared  since  the  revival  of  learning.  It  was  pub- 
lished in  1797,  nearly  twenty  years  before  the  first  of 
Lamarck's  volumes  appeared.  *  That  it  was  well  known 
to  the  latter  can  hardly  be  doubted,  when  we  see  no  less 
than  ten  genera  similarly  named  by  both ;  and  that 
almost  every  genus  of  Lamarck's  univalves  are  found  in 
this  list,  under  different,  but  less  classical,  names.  Of 
univalves,  Humphrey  has  87,  contained  in  the  single 
collection  of  which  his  book  is  a  catalogue.  How  many 
more  he  had  determined  to  name,  does  not,  of  course, 
appear  ;  but  the  total  number  of  Lamarck's  is  but  Q6, 
for  the  whole  of  the  testaceous  gastropods. 

(19.)  Lamarck's  system,  so  far  as  regards  the  animals 
now  before  us,  may  be  thus  briefly  stated.  He  arranges 
the  whole  group  under  the  two  classes  of —  I.  Con- 
chifera;  and,  IL  Mollusca.  The  first  contains  the 
bivalve  shell-fish,  and  is  again  divided  into  two  orders  : 
one  of  these  is  called  Conchiferes  dimyaires,  the  in- 
terior of  the  shells  presenting  two  muscular  impressions, 
separated  and  lateral ;  while  in  those  of  the  second 
order,  or  ConcJuferes  monompaires,  there  is  but  one 
muscular  impression,  placed  nearly  in  the  centre,  —  the 
muscle  itself  being  single,  and  which  appears  to  run 
through  the  body  of  the  animal.  Each  of  these  great 
divisions  of  bivalves  contains  several  others,  denominated 
sections,  chiefly  differing  in  the  structure  of  their  feet. 

Order  I.     CONCHIFITRES  DIMYAIRES. 


Section  1. 

Mya. 

Amphidesma. 

Aspergiliuin. 

Anatina. 

Corbula. 

Clavagella. 

Pandora. 

Fistularia. 

Sect. 

TI. 

Saxicava. 

Septaria. 

Conch,  tenuipedes. 

Petricola. 

Teredina. 

Lutraria. 

Venerirupis. 

Pholas. 

Mactra. 

Sanguinolaria. 

Gastrochaena. 

Crassalella. 

Psammobia. 

Solen. 

Erycina. 

Psammota;a. 

Panopa?a. 

Ungulina. 

Tellina. 

Glycimeris. 

Solenimya. 

Tellinides. 

*  The  first  volume  of  the  Hist.  Nat.  des  Animaux  sans  Verthbres  bears 
the  date  of  March,  1815. 


CHAP.  I. 

■ 

SYSTE3I    OF 

LA3IARCK.                                      ^ 

Corbis. 

Cytberea. 

Trigonia. 

Lucina. 

Venus. 

Castalia. 

Donax. 

Venericardia 

Unio. 

Capsa. 

Cardium. 

Hyria. 

Crassina, 

Cardita. 
Cypricardia. 

Anodon. 
Iridina. 

Sect. 

III. 

Hiatella. 

Conch,  lamellipedes. 

Isocardia. 

Sect.  IV. 

Cyclas. 

Cuculzea. 

Conch,  ambigus. 

Cyrena. 

Area. 

Diceras. 

Galathea. 

Pectunculus. 

■  Chama. 

Cyprina. 

Nucula. 

• 

Etheria. 

Order  II.    CONCH. 

MONOMYAIRES. 

Section  I. 

Sect. 

II. 

Sect.  III. 

Tridacna. 

Pedum. 

Branchiopoda  Cuv, 

Hippopus. 

Lima. 

Sphserulites. 

Modiola. 

Plagiostoma. 

Radiolites. 

Mytilis. 

Pecten. 

Calceola. 

Pinna. 

Plicatula. 

Birostrites. 

Crenatula. 

Spondylus. 

Discina. 

Perna. 

Podopsis. 

Crania. 

Malleus. 

Grypheea. 

Orbicula. 

Avicula. 

Ostrea. 

n^prphratula. 

Meleagrina. 

Vulsella. 
Placuna. 
Anonica. 

Lingula. 

23 


(20.)  To  his  second  great  division^  Lamarck  restricts 
the  title  oi Mollusca  :  these  he  again  subdivides  into  the 
five  following  orders  :  —  1 .  The  Pteropoda,  which  forms 
a  part  of  our  Cephalopoda.  2.  The  Hydrohranchia^ 
which  includes  the  JVudibranchia,  Scutihranchia,  and 
Tectibranchia  of  Cuvier  ;  together  with  the  genera  On- 
chidium,  ParmaceUa,  Limax,  Testacellus,  and  Vitrina  : 
these  genera  he  places  in  his  section  Pneumobranchia, 
and  makes  them  the  passage  to  his  tlm^d  order,  or  the 
Trachelipodes,  in  which  all  the  univalve  shells  are  placed. 
The  foiu'th  order  is  composed  of  the  Cephalopoda,  or 
cuttlefish ;  and  the  fifth  contains  the  Heteropoda. 
The  genera  belonging  to  each  of  these  orders  are  as 
follows  :  — 


Order  I.      PTEROPODA. 


Hyalaea. 
Ciio. 


Cleodora. 
Limacina. 


4 


Cymbulia. 
Pneuraodermon. 


5J* 

SHELLS    AND    SHELL- 

-FISH.                   PART  I 

Order  H.     GASTEROPODES. 

Section  I. 

Pleurobranchus. 

Bulla. 

Glaucus. 

Umbrella. 

Aplysia. 

Eolis. 

Parmophora. 

Dolabella. 

Tritonia. 

Emarginula. 

Scyllaea. 

Fissurella. 

Sect.  II. 

Tethys. 

Pileopsis. 

Onchidium. 

Doris. 

Calyptraa. 

Parmacella. 

Phyllidia. 

Crepidula. 

Limax. 

Chitonellus. 

Ancylus. 

Testacella. 

Chiton. 

Acera. 

Vithna. 

Patella. 

BuUaea. 

Order  HI.    TRACHELIPODES. 

Section  I. 

Haliotis. 

Triton. 

Les  Phytiphages.        Tornatella. 

Rostellaria. 

Helix. 

Pyramidella. 

Pteroceras. 

Carocolla. 

"Vermetus.         ^ 

Strombus. 

Anastoma. 

Scalaria. 

Cassidaria. 

Helicina. 

Delphinula. 

Cassis. 

Pupa. 

Solarium. 

Ricinula. 

Clausilia. 

Rotella. 

Purpura. 

Bulimus. 

Trochus. 

Monoceros. 

Achatina. 

Moiiodonta. 

Concholepas. 

Cyclostoma. 

Turbo. 

Harpa. 

Planorbis. 

Planaxis. 

Dolium. 

Physa. 

Phasianella. 

Buccinum. 

Lymneea. 

Turritella. 

Eburna. 

Melania. 

Terebra. 

Melanopsis. 

SECT.:n. 

Columbella. 

Pirena. 

L.es  Zoophages. 

Mitra. 

Valvata. 

Cerithium. 

Voluta. 

Paludina. 

Pleurotoma. 

Marginella. 

Ampullaria. 

Turbinella. 

Volvaria. 

Navicella. 

Cancellaria. 

Ovula. 

Neritina 

Fasciolaria. 

Cypraea. 

Natica. 

Fusus. 

Terebellum.  ; 

lanthina. 

Pyrula. 

Ancillaria. 

Sigeretus. 

Struthiolaria. 

Oliva. 

Stomatella. 

Ranella. 

Conus. 

Stomatia. 

Murex. 

Order  IV.    CEPHALOPODES. 

Section  I. 

Spirula. 

Melania. 

Testaceous  Cephalo-      Spirolina. 

Rotelia. 

poda. 

Lituola. 

Lenticulina. 

* 

Belemnites. 

Renulina. 

Placentula. 

Orthocera. 

Christcllaria. 

Discorbis. 

Nodosaria. 

Orbiculina. 

Siderolites. 

Hippiirites. 
Conilites. 

Miliola. 
Gyrogona. 

Polystomella. 
Vorticialis. 

CHAP.  I.  SYSTEM    OF    CUVIER.  25 

NummuUtes.  Baculites.                                     Sect.  III. 
Nautilus.                                                                               (^epf^-  Cepiaria. 

Ammonites.  Sect.  II.  Octopus. 

Orbiculites.  Ceph.  Monothalama.  Loligopsis. 

Ammonoceras.  Argonauta.  Loligo. 

Turrilites.  Sepia. 

;    Order  V.    HETEROPODA. 

Carinaria.  Pterotrachia.  Phylliroe. 

(21.)  The  system  of  M.  Cuvier  difFers,  in  many  re- 
spects^ from  the  above.  The  Mollusca  form  the  second 
great  division  into  which  this  admirable  anatomist  divides 
the  animal  kingdom.  These  he  distributes  under  six 
principal  classes :  1 .  Cephalopoda,  or  cuttlefish ;  2. 
Pteropoda,  or  clios  ;  3.  Gasteropoda,  an  immense  and 
heterogeneous  assemblage,  which  we  shall  presently 
notice  in  detail ;  4.  Acephala,  or  bivalve  Testacea,  at 
the  end  of  which  he  introduces  the  tunicated  Mollusca 
{Tanicata  Sav.)  ;  5. Branchiopoda,  or  anomian  shells  ; 
6.  Cirripedes,  or  barnacles.  The  great  variety  of  ani- 
mals brought  together  in  the  third  order,  Gasteropoda, 
obhges  our  author  to  divide  it  into  others,  the  names  and 
contents  of  which  are  as  follows  :  — 1.  Pulmonia,  con- 
tains  the  slugs  and  snails,  both  terrestrial  and  fluviatile. 

2.  NuDiBRANCHiA,  iucludes  all  the  naked  marine  Tes- 
tacea without  shells,  —  as   Triton,  Doris,  Thethys,  &c. 

3.  Inferobranchia,  consists  but  of  two  genera,  Phyl- 
lidia  and  Diphyllidia.  4.  Tectibranchia,  compre- 
hends the  Bulla  family  and  the  Aphjsia.  5.  Hetero- 
PODA,  embraces  the  Firoles  and  the  CariiiaricE.  6.  Pec- 
TiNiBRANCHiA  :  Under  this  order,  arranged  in  sections, 
are  placed  the  whole  of  the  Trochus  and  Turbo  families, 
together  with  the  greatest  part  of  the  marine  univalve 
Testacea.  7-  Tubulibranchta,  is  limited  to  the  genera 
Vermetus,  Magilis,  and  Siliquaria.  8.  Scutibranchia, 
contains  Haliotis,  Fissurella,  and  Emarginula  :  while 
the  9th  and  last  order,  Cyclobranchia,  consists  but 
of  Patella  and  Chiton.  To  go  into  further  detail  will 
be  needless,  since  the  student  will  at  once  arrive  at  a 
general  idea  on  the  contents  of  these  groups,  by  the  indi- 
cations already  given. 


26 


SHELLS    AND    SHELL-FISH.  PART  I. 


(22.)  In  both  these  latter  methods  of  classifymg  the 
Testacea,  there  is  much  to  approve  and  much  to  dissent 
from.  It  is  clear  that  neither  of  these  naturalists^  how- 
ever great  their  merits  undoubtedly  are  in  other  respects, 
have  paid  any  attention  to  the  difference  between  analogy 
and  affinity  :  nor  have  they  aimed  at  anything  beyond 
producing  a  simple  scale  or  line  of  connection  from  one 
group  to  another.  Now,  as  no  such  simple  series  exists 
in  nature,  —  whose  relations  of  affinity  are  always 
double,  and  generally  treble,  and  whose  analogies  are 
interminable,  —  it  follows,  as  a  matter  of  course,  that 
both  have  completely  failed  in  laying  down  a  simple 
graduated  scale  of  the  objects  before  them.  Hence,  as 
the  groundwork  of  both  systems  is  founded  in  error, 
no  apology  is  necessary  for  rejecting  them,  particularly 
when  the  object  sought  for  is  the  discovery  of  the  na- 
tural arrangement.  It  is  time,  however,  to  leave  the 
systems  of  others,  and  to  lay  before  the  naturalist  some 
details  of  that  here  proposed. 


CHAP.  II. 

ON  THE  TESTACEOUS  MOLLUSCA  IN  GENERAL,  THE  PRIMARY 
DIVISIONS,  AND  THEIR  ANALOGIES  TO  THE  VERTEBRATA  AND 
ANNULOSA. 

(23.)  The  testaceous  mollusks,  or  shell-fish,  with  few 
exceptions  *,  are  all  marine,  or,  at  least,  aquatic  animals, 
soft  and  slimy  in  their  nature,  and  without  articulated 
limbs,  so  that  such  as  can  move  about,  crawl  upon 
their  belly,  or  swim  in  the  water  by  means  of  the  fin- 
shaped  lobes  of  their  mantle.  Independent  of  their 
peculiar  anatomical  structure,  and  merely  looking  to 
external  characters,  the  most  perfect  of  the  testaceous 

*  Some  of  the  parasitic  groups,  and  the  land  shells,  or  slugs. 


CHAP.  ir.  TESTACEOUS    MOLLUSKS    GENERALLY.  27 

tribes  are  at  once  known^  either  by  being  covered  with 
a  hard  shelly  or^  if  without  this  protection,  by  having 
white  blood,  and  being  destitute  of  any  processes  which 
perform  the  office  of  feet.  Many,  indeed,  are  fixed  to 
the  surface  of  rocks,  and  other  substances,  where  they 
remain  during  life ;  while  others  bore  for  themselves 
internal  cavities,  or  cells,  in  which  they  take  up  their  per- 
manent habitation;  while  the  least  organised  are  parasitic. 
The  similarity  of  some  of  the  naked  Testacea  to  XheAnne- 
lides,  or  sea-worms,  is  so  great,  that  the  older  naturalists 
classed  them  together  ;  and  even  to  this  day  we  find  a 
whole  division  mixed  up  with  the  annulose  Vermes,  or 
true  intestinal  worms.  Let  the  student,  however,  bear 
in  mind  that  the  animals  of  which  we  are  now  speaking 
have  neither  joints  to  their  bodies  or  limbs,  nor  any  pro- 
cesses, by  which  they  can  crawl ;  and  that  their  blood 
is  white,  and  not,  as  in  the  Annelides,  red.  Further- 
more, the  testaceous  Mollusca  never  assume  the  shape 
of  the  polypes ;  nor  do  they  possess  that  radiated  form 
and  arrangement  of  filaments,  which  give  such  a  pecu- 
liar aspect  to  the  Radiata.  By  these  circumstances, 
therefore,  the  observer  may  discriminate,  in  ordinary 
cases,  the  characteristic  marks  of  even  the  aberrant  or 
less  perfect  Testacea  ;  while  he  can  be  in  no  doubt  as 
to  those  which  constitute  the  types.  The  perfection  of 
the  class  is  seen  in  those  animals  whose  body  is  pro- 
tected by  a  hard  calcareous  covering,  or  shell,  either  in 
the  form  of  a  twisted  or  convoluted  cone,  variously 
modified,  or  composed  of  two  principal  valves  or 
pieces,  more  or  less  flattened,  and  united  by  a  cartila- 
ginous hinge.  These  shells  are  generally  ornamented 
with  a  variety  of  colours,  and  are  frequently  polished, 
on  their  external  surface,  in  the  most  beautiful  and 
perfect  manner,  by  the  animals  themselves.  The  single 
shells  are  called  Univalves,  and  such  is  the  periwinkle 
and  snail ;  while  the  double  are  termed  Bivalves,  and 
are  exemplified  in  the  oyster  and  the  cockle.  As 
nature,  however,  proceeds  from  one  to  the  other  of 
these  groups  by  gradations  of  structure,  we  consequently 


28  SHELLS    AND    SHELL-FISH.  PART  I. 

find  a  few  bivalves  which  assume  the  appearance  of 
univalves  ;  and  others  which,  from  the  valves  being 
more  than  two,  were  called  by  Linnaeus  Multivalve 
shells.  This  term  the  great  Swede  applied  not  only  to 
those  animals  which  really  belonged  to  the  Testacea,  but 
to  the  Cirripedes,  or  barnacles,  which  have  nothing  to 
do  with  shells,  properly  so  called.  The  term,  there- 
fore, is  altogether  objectionable,  and  will  not  here  be 
employed. 

(24.)  Such  are  the  leading  external  distinctions  of  the 
class  of  animals  now  before  us.  Their  typical  characters 
are  three  ;  two  positive,  the  other  negative.  The  first  is 
that  of  crawling  upon  their  belly,  yet  without  feet; 
the  second  is  their  being  covered  with  a  beautiful  calca- 
reous shell,  which  is  their  constant  habitation,  and 
which  they  have  the  power  of  enlarging,  to  suit  the 
progressive  growth  of  their  soft  bodies  ;  the  third  is, 
that,  if  deprived  of  this  covering,  they  have  not  the 
least  vestige  of  rings  or  joints  on  their  bodies  :  the 
mouth,  indeed,  may  be  circular,  and  even  the  branchia, 
but  this  is  the  only  analogy  they  have  to  the  Radiata. 
In  proportion  as  nature  recedes  from  this  typical 
eminence,  the  structure  of  the  shell  becomes  imperfect, 
until,  in  the  aberrant  groups,  the  animal  is  either  naked, 
or  is  but  partially  protected  by  such  a  covering. 

(25.)  The  Testacea,  considered  anatomically,  may 
be  described  as  soft  inarticulate  animals,  almost  always 
breathing  by  branchia,  or  lungs,  which  vary,  however, 
in  the  most  singular  diversity  of  ways  both  as  to  form 
and  situation  ;  this  variation,  moreover,  takes  place  in 
groups  so  closely  related  to  each  other  in  all  other  re- 
spects, that  it  is  perfectly  clear  no  natural  arrangement 
can  be  founded  upon  the  organs  of  respiration.  The 
least  organised,  in  fact,  such  as  the  PlanaricB,  &c.,  have 
no  branchia  whatever  ;  so  that  they  only  possess  two  of 
the  characters  of  the  class, —  namely,  a  flattened  disk  or 
disks,  which  act  as  a  foot,  and  a  total  absence  of  joints 
in  their  body.  Their  blood  is  white,  and  its  circulation, 
observes  Cuvier,  is  always  double  ;  that  is,  their  pul- 


CHAP.  IT.  TESTACEOUS    MOLLUSKS    GENERALLY.  2Q 

monary  circulation  describes  a  separate  and  distinct 
circle.  As  for  their  manner  of  reproduction,  it  is  even 
more  variable  and  diversified  than  their  mode  of  re- 
spiration. In  some,  as  with  Gasteropoda,  there  is  a 
head  with  tentacula  and  eyes,  either  slightly  or  very 
fully  developed  ;  while  in  the  Dithyra,  or  bivalves,  all 
these  parts  are  wanting.  Nearly  all,  however,  have  a 
developement  of  the  skin  which  covers  their  body,  which 
bears  more  or  less  resemblance  to  a  mantle :  but  even 
this  assumes  innumerable  shapes;  —  sometimes  it  is  di- 
lated in  the  form  of  wing-like  fins  ;  in  others,  as  the  car- 
nivorous Gasteropoda,  it  becomes  a  syphon  by  which  the 
animal  breathes.  In  the  naked  Testacea,  the  mantle  is 
simply  membranaceous,  coriaceous,  or  fleshy.  It  is,  in 
fact,  utterly  impossible  to  give  such  a  general  detail  of 
this  diversified  class,  either  in  respect  to  external  or 
internal  anatomy,  as  will  not  be  subject  to  innumerable 
exceptions  at  every  step.  All  the  modes  of  mastication 
and  deglutition,  as  Cuvier  says,  are  found  among  these 
animals  ;  their  stomachs  are  sometimes  simple,  some- 
times multiple.  They  also  present  examples  of  all  the 
modes  of  generation  ;  and  the  same  learned  anatomist 
confesses  that  "  these  varieties  of  the  digestive  and  ge- 
nerative processes  are  found  in  the  same  order,  and 
sometimes  in  the  same  family."  *  Hence  it  inevi- 
tably follows,  that  any  system  founded  solely  on  any 
one  or  more  of  these  anatomical  considerations,  is  sure 
to  be  not  only  unnatural,  but  perfectly  unintelligible 
to  the  great  bulk  of  naturalists,  who  are  referred  to  the 
soft  parts  of  an  animal  which  they  never  saw,  and 
cannot  procure.  In  regard  to  the  nervous  system, 
Mr.  MacLeay  has  well  observed,  that  "  the  most  ge- 
neral notion  we  can  form,  at  present,  of  the  nervous 
system  of  the  Molhisca,  is,  that  the  medullary  collar,  in 
the  more  typical  groups,  must  always,  in  its  circum- 
ference, contain  four  ganglions,  which  may  either  be 
united  two  and  two,  as  it  is  probable  they  are  in  the 

*  Griff.  Cuv.  p.  4. 


30  SHELLS    AND    SHELL-FISH.  PART  I. 

AcephaJa  (Dithyra),  or  all  four  together,  as  in  Tritonia. 
The  brain  is  always  composed  of  two  of  these  lobes, 
which  are  generally  connected,  as  in  Aplysia,  or  some- 
times separate,  as  in  Haliotis  and  Patella :  the  remaining 
two  ganglions  of  the  collar  send  off  nerves  to  the  or- 
gans of  respiration,  &c.,  and  are  either  united  together, 
as  in  the  common  slug  and  Patella,  or  are  separate,  as 
in  Aplysia."  It  is  time,  however,  to  quit  these  ge- 
neralities, and  enter  into  more  definite  details. 

(26.)  A  rapid  survey  of  the  general  peculiarities  of  the 
class  will  not,  how^ever,  be  here  misplaced.  We  have  said 
that  these  animals  have  no  distinct  feet,  or  any  organs 
which,  by  forming  appendages  to  their  body,  supply  their 
want.    It  is,  however,  customary  —  although  the  appella- 
tion is  certainly  incorrect  —  to  call  that  part  of  the  body 
which  is  next  to  the  ground,  and  which  is  generally  smooth 
and  flattened,  the  foot,  when,  in  fact,  it  is  merely  the 
belly,  assuming  only  the  office  of  a  foot,  and  the  shape 
of  a  sucker :   by  alternately   contracting  and  extending 
this  part,  the  animal  moves  forward,  —  slowly,  indeed, 
but  very  surely.      The  aquatic  species  are  able  to  crawl 
on  marine  rocks,  even  when  the  sea  is  greatly  agitated  ; 
and  every  one  knows  the  tenacity  with  ^vhich  a   slug 
will  adhere  to  the  substance  from  wdiich  we  attempt  to 
remove  it.     This  is   at   once   explained  by  the  smooth 
disc  of  the  belly  acting  as  a  sucker,  like  the  tail  of  the 
leech.      This  mode   of  progression   is   almost  universal 
among  the  Gasteropoda,  or  univalve  shell-fish  ;  but,  in 
the  bivalves,  the  body  of  the  animal  is  frequently  length- 
ened behind,  so  as  to  assume  a  much  more  analogous 
appearance  of  a  foot  than  what  we  find  in  others.     The 
common  cockle  is  one  of  the  best,  as  it  is  one  of  the 
most  familiar,  instances  of  this  structure.     Those  who 
have  watched  these  animals  at  the  ebb  of  tide,  know 
that  they  leap  very  frequently  ;  but  on  their  method  of 
doing  this  two  opinions  have  been  given :    some  main- 
tain that  the   foot,   which,    when  protruded,  forms   a 
sharp  angle,    is  the  chief  organ  made   use  of;   while 
others  assert  that  this  motion  is  caused  by  the  sudden 


CHAP.  ir.         TESTACEOUS    MOLLUSKS    GENERALLY.  31 

shutting   of  the   shelly  valves,  which  produces  a  jerk. 
In  some  very  few  instances  among  the  typical  Testacea, 
as  in  the  genus  lanthina,  or  oceanic   snail;,  the  animal 
has  a  cellular  organ  attached  to  the  belly,  by  which  it 
floats  on  the  surface  of  the  ocean,  or  sinks  to  the  bottom, 
at  its  own  pleasm-e.      The  power   of  swimming,  how- 
ever, is  chiefly  found  among  the   aberrant  groups,  such 
as    the  cuttlefish    (^Cephalopoda),    the   tritons    {JVudi- 
hranchia),  and  the    Tectibranchia  :    the  first  of  these 
may  really  be  said  to  possess  Jins  ;  while  the  naked  tri- 
tons, no  doubt,  use  the  appendages  of  the  body  for  the 
same  purpose.    The  power  of  adhesion  is  also  diflferently 
bestowed  :   in  the  cuttlefish  and  Planar  ice,  it  resides  in 
the  innumerable   suckers  which    terminate  the  arms  of 
one,  and  are  placed  on  the  under  side  of  the  other.      In 
the  limpet  {Patella),  the  ear-shell  (Haliotis),  and  the 
chiton,   it   originates  in   the   excessive   breadth   of  the 
disk  upon  the  belly,  which  covers  a  surface  equal  to  that 
of  the  whole  animal  and  its   shell :   so   firmly,  indeed, 
do  these  genera  adhere  to  the  rocks  or  other  substances 
upon  which  they  are  found,  that  they  can  only  be  sepa- 
rated by  great  force.      It  is  among  the  limpets  that  we 
find  the  power  of  locomotion  at  its  lowest  ebb  ;  for  they 
seldom  remove  far  from  the  spot  on  which  they  were 
born  ;  and  many,  from  the  shape   of  the  shell  corre- 
sponding to  the  surface  of  the  rock,  appear  never  to 
have   done  this :    finally,  in    the  genus   Hipponix,  we 
arrive  at  a  positive  certainty  that  the  animal  is  fixed, 
because  it  adheres  by  a  separate  distinct  plate,  which 
thus,  in  point  of  fact,  renders  it  a  bivalve  shell.      At- 
tachment, however,  is  much  more  prevalent  among  the 
bivalves,  where  we  have  entire  families  fixed  to  marine 
substances,  either  by  one  of  these  valves,  as  the  oysters, 
or  by  a  packet  of  strong  fibrous  threads.      The  attached 
genera  are  much  less  numerous  than  the  others,  and  are 
affixed  in  different  ways.    Some,  like  the  muscles  {My- 
tilus),  are  merely  connected   into  little  bunches  or  fa- 
milies, by  slender  and  scattered  threads,  strong  enough 
to  keep  them  together ;  others,  as  the  Pinna',  or  wing- 


32  SHELLS    AND    SHELL-FISH.  PART  I. 

shells,  are  provided  with  a  thick  tuft  of  silky  hairs, 
called  a  byssus,  which  issues  from  one  side  only  of  the 
shell,  the  other  end  being  firmly  attached  to  m.arine 
bodies.  In  both  these  families,  however,  there  is  still 
some  slight  locomotive  power  left;  for,  although  the 
animal  does  not,  and  probably  cannot,  quit  the  spot  by 
disengaging  its  byssus,  and  mooring  itself  to  another 
station,  still  it  is  not  rendered  absolutely  motionless  : 
the  waves  can  move  the  shell  backwards  and  forwards, 
and  the  fish  may  be  compared  to  a  horse  or  other 
animal  fastened  by  a  very  short  rope,  which,  neverthe- 
less, permits  him  to  move  his  body  and  limbs.  In  the 
Pholas,  we  have  the  next  step  towards  an  absolute  ex- 
tinction of  the  power  of  moving.  These  shell-fish  have 
no  byssus,  nor  are  they  affixed  by  any  other  method  ; 
yet,  soon  after  birth,  they  perforate  the  substance  upon 
which  they  have  been  deposited  by  the  parent,  and  ex- 
cavate for  themselves  deep  burrows,  or  caves,  exactly  of 
the  circumference  of  their  own  shells  ;  and  in  these 
hollows  they  take  up  their  permanent  residence.  It  is 
not  absolutely  ascertained,  indeed,  that  these  boring 
Testacea  cannot  quit  their  first  habitation  for  another  ; 
but  there  are  many  reasons  to  authorise  the  supposition 
that  they  live  and  die  in  the  same  which  they  excavated 
when  young,  and  which  they  have  the  power  of  en- 
larging as  they  increase  in  size.  A\^ithin  such  a  narrow 
compass,  it  is  obvious  that  the  Pholas  is  more  a  prisoner 
than  the  Pinna  or  the  Terehratula,  because  the  walls 
of  its  habitation  keep  it  immoveable,  so  that  even  the 
agitation  of  the  waves  cannot  give  it  that  undulating 
motion  enjoyed  by  the  byssiferous  families.  Finally, 
we  come  to  such  as  are  absolutely  cemented  by  one  of 
their  valves  to  rocks  or  stones^  or  to  each  other  :  many 
of  the  oysters  are  of  this  description  ;  but  the  most  con- 
spicuous are  the  different  species  of  Chama  and  spon- 
dyles  ;  several  of  which  have  the  entire  surface  of  one 
valve  fastened  by  a  calcareous  deposition  to  rocks,  pieces 
of  floating  timber,  and  to  the  bottoms  of  ships.  It  is, 
consequently,  in  these  families,  and  in  the  worm-shells. 


CHAP.  II.         TESTACEOUS    ANIMALS    IN    GENERAL.  33 

that  we  have  the  most  perfect  examples  of  the  sedentary 
Testacea. 

(27.)  Although  the  head,  where  it  exists,  of  the  Tes- 
tacea, is  very  different  from  that  of  vertebrated  and 
annulose  animals,  —  inasmuch  as  it  is  not  separated, 
from  the  body  by  a  neck,  — it  is  yet  to  be  distinguished, 
in  many  groups,  by  the  presence  of  tentacula,  or  feelers, 
and  by  two  or  four  black  dots,  which  are  generally  con- 
sidered to  be  the  organs  of  sight :  in  proportion  as  we 
advance  from  the  PlanaricE  on  one  side,  and  from  the 
chitons  on  the  other,  towards  the  cuttlefish,  we  find 
the  head  and  the  eyes  gradually  assuming  that  definite 
shape  and  structure  which  are  so  characteristic  of  the 
vertebrated  animals.  Some  of  the  tritons  (^Nudi- 
branchia),  and  all  the  bivalve  shell-fish  (^Dithyra),  have 
no  indication  of  eyes,  nor  have  the  latter  any  obvious 
head  ;  but  in  the  Gasteropoda,  or  univalves,  both  begin 
to  appear.  We  see  this  in  the  garden  snail,  and  in  all 
the  freshwater  and  marine  animals  of  this  tribe.  In 
the  StromhidcB  and  the  Volutidcp,  the  eye  is  nearly  as 
perfect  as  that  of  the  cuttlefish.  From  this  group, 
however,  nature  again  recedes ;  and  in  the  Pteropoda, 
although  the  general  form  is  preserved,  the  head  is  once 
more  confounded  with  the  body,  and  the  eyes  disap- 
pear. 

(28.)  On  the  habits,  food,  and  geographic  distribu- 
tion of  the  Testacea  we  can  say  but  little  w^hich  is 
applicable  to  all.  The  great  majority  are  aquatic  and 
marine ;  but  two  or  three  extensive  families  are  found 
only  in  fresh  water.  The  land  shells  are  exceed- 
ingly abundant  in  species,  and  the  gastropod  worms 
are  parasitic  in  or  upon  other  animals.  It  may  be  here 
remarked,  that  all  the  bivalves  (Dithyra)  are  aquatic, 
but  that  the  univalves  inhabit  the  different  situations 
just  enumerated.  The  food  of  all  these  creatures  varies 
according  to  their  own  particular  races.  A  large  num- 
ber (forming  the  phytophagous  gastropods)  feed  almost 
only  upon  living  vegetables,  either  terrestrial  or  aquatic, 
—  as  the  snail  of  our  gardens,  and  the  periwinkle  of  our 

D 


34  SHELLS    AND    SHELL-FISH.  PART    I. 

coasts  ;  but  a  still  greater  assemblage  are  carnivorous,  — 
devouring  not  only  living,  but  dead,  animals,  and  even 
attacking  other  tribes  of  their  own  class.  It  Avould  be 
interesting  to  know  in  what  manner  nature  has  pro- 
vided for  the  sustenance  of  such  as  are  permanently 
affixed  to  one  spot.  Some  of  these  have  divers  me- 
thods of  exciting  little  currents  in  the  water,  by  Avhicli 
means  fresh  portions  of  it  are  brought  to  the  mouth, 
along  with  which  such  minute  animals  or  fragments  of 
vegetables  as  are  adapted  for  food  are  secured.  The 
branchipodous  bivalves,  like  the  TerehratulcB,  although 
sedentary,  are  provided  with  long  fringed  processes, 
which  are,  no  doubt,  employed  to  capture  their  prey, 
in  a  similar  manner  to  the  arms  of  the  Cirripedes,  or 
barnacles;  while  the  cuttlefish  (C6';^//«/o/)06?a)  and  the 
Tritonia  swim  about  in  search  of  marine  animals 
weaker  than  themselves.  In  regard  to  their  geographic 
distribution,  much  might  be  said,  did  we  not  fear 
being  drawn  into  longer  details  than  our  space  would 
permit.  It  will  be  only  necessary  to  observe  in  this 
place,  that  the  geographic  range  of  the  Testacea  is  not 
so  wide  or  uncircumscribed  as  the  generality  of  authors 
assert.  Tropical  latitudes,  as  usual,  display  a  greater 
variety  of  species,  and  a  larger  number  of  individuals, 
than  those  seas  which  lie  under  temperate  or  frigid 
skies.  The  Testacea  of  Europe  are  as  distinct  from 
those  of  America,  as  the  latter  are  from  those  of  Aus- 
tralia, Africa,  or  Asia.  We  have  already  illustrated 
this  fact  in  that  part  of  our  series  devoted  to  the  geo- 
graphic distribution  of  animals ;  and  it  may  be  safely 
asserted  that  the  grand  features  of  zoological  geography 
are  as  conspicuous  in  this  class  of  animals,  as  in  any 
other. 

(29.)  The  great  natural  divisions  of  the  testaceous 
Mollusca  appear  to  us  to  be  these  :  —  The  first,  or 
pre-eminently  typical,  are  unquestionably  the  Gastero- 
poda, or  spiral  univalves,  whether  we  consider  the 
comparative  perfection  of  their  internal  or  their  external 
structure.      The  second,   or  sub-typical    class,  is  com- 


CHAP.  II.  PRIMARY    DIVISIONS    OF    TESTACEA.  35 

posed  of  the  Dithyra  of  Aristotle^  or  the  bivalves_, 
whose  structure  is  less  perfect^  but  which  are  in  like 
manner  protected  by  a  regularly  formed,  and  often 
richly  coloured,  bivalve  shell.  The  third,  or  aberrant 
group,  as  usual,  comprehends  three  :  1 .  The  Nudibran- 
CHiA  of  jVI.  Cuvier,  or  the  naked  Gasteropoda  ;  2.  The 
Pa renchymata,  or  intestinal  Testacea;  and,  S.TheCE- 
PHALOPODA,  or  cuttlefish.  We  shall  first  slightly  glance 
at  the  leading  characters  of  each  of  these  classes,  and 
then  endeavour  to  trace  their  analogies  to  other  animals. 
(30.)  Under  the  name  of  Gasteropoda,  we  retain 
the  greater  number  of  Cuvier's  divisions*;  but  the  most 
typical  consists  of  the  univalve  or  spiral  Testacea,  whose 
body  is  protected  and  generally  coveredt  by  a  calcareous 
shell :  the  head,  although  not  assuming  a  very  decided 
shape,  is  always  present,  and  is,  in  almost  all  instances, 
at  once  distinguished  by  having  two  or  more  tentacula, 
assuming  the  appearance  of  the  antennse  and  the  palpi 
of  insects.  All  the  true  Gasteropoda  possess  the  rudi- 
ments of  eyes ;  in  the  generality,  these  organs  appear 
in  the  form  of  black  specks,  either  at  the  tips  of  the 
longest  pair  of  tentacula,  as  in  the  common  snail,  or  at 
their  base.  "We  thus  find  that  the  true  Gasteropoda 
possess  four  primary  characters,  —  the  power  of  crawling 
upon  their  belly,  the  possession  of  a  head  and  eyes, 
and,  finally,  the  protection  of  a  shell.  Those  which 
are  most  remote  from  the  point  of  perfection,  and 
which  form  the  links  of  connection  to  other  classes  (as 
the  Tectihranchia  on  one  side,  and  the  Nudihranchia 
on  the  other),  have  some  one,  or,  perhaps,  two,  of  these 
characters  either  lost,  or  but  very  imperfectly  developed; 
these,  in  short,  are  the  aberrant  groups,  and  must  never 
be  looked  to  for  the  right  understanding  of  the  class  to 
which  they  belong.  The  slug,  for  instance,  has  no 
shell,  or  merely  the  rudiments  of  one  ;  yet  it  crawls 
upon  its  belly,  it  is  furnished  with  a  distinct  head  and 
even  jaws,  it  has  four  tentacula,  and  a  pair  of  rudi- 

*  As  the  Heteropoda,  Cydobranchia,  Scutibranchia,  and  Pulsnonaria. 
t  Except  in  Limax,  Sec. 

D    2 


36  SHELLS    AND    SHELL-FISH.  PART  I. 

mentary  eyes  ;  it  presents  us,  in  fact,  with  all  the  cha- 
racters of  a  testaceous  gastropod,  except  one, — that  of 
being  covered  by  a  shell.  In  the  Tectihrunchia,  again, 
v/e  have  a  group  still  more  remote  from  the  typical 
structure  ;  for  many  of  these  have  the  mere  rudiments  of 
a  shell  covering  a  small  part  of  their  body,  and  they  swim 
as  much  as  they  crawl.  Yet  their  evident  connection  to 
the  VolutidcB  (by  means  of  the  Cyprcfidcp)  on  one  side, 
and  to  the  chitons  on  the  other,  points  them  out  as  truly 
belonging  to  this  order. 

(31.)  The  DiTHYRA  of  Aristotle,  or  bivalve  shells, 
form  the  next,  or  sub-typical  division.  This  comprises 
animals  destitute  of  an  apparent  head,  but  still  inclosed 
in  a  shell,  and  still  moving  on  the  belly.  There  is  not, 
however,  in  this  latter  part,  any  flattened  disk  ;  and  the 
shell,  instead  of  being  spiral,  is  generally  composed  of 
•  two  pieces,  or  valves,  joined  together  by  a  horny  liga- 
ment. The  Dithyra,  moreover,  are  further  distin- 
guished by  having  neither  tentacula,  nor  the  least 
vestige  of  eyes.  We  meet  with  some,  indeed,  as  the 
Chelisom(jP,  which  have  no  external  shelly  covering ; 
and  others,  where  the  bivalve  shell  is  inclosed  in  a 
tube,  as  the  family  of  TuhuUhranchia,  —  thus  assuming 
the  disguise  of  a  univalve.  But  these  remarkable  de- 
viations are  few,  and  point  out,  as  we  have  just  men- 
tioned, the  extreme  limits  of  the  tribe. 

(32.)  The  NuDiBRANCHiA,  or  tritons  (part  of  the 
naked  Gasteropoda  of  i\I.  Cuvier),  form  the  third  of 
our  principal  divisions,  and  are  all  no  less  strongly  cha- 
racterised. Destitute  of  any  covering,  and  presenting 
a  marked  peculiarity  in  their  external  branchia,  their 
appearance  is  so  very  different,  that  every  unprejudiced 
observer  cannot  but  wonder  they  should,  up  to  this  day, 
have  been  mixed  up  with  the  true  gastropod  shell-fish. 
These  animals,  in  fact,  are  entirely  flattened,  naked, 
soft,  and  gt^nerally  ornamented  with  beautiful  colours  ; 
they  move  about  by  means  of  their  foot,  or  concave 
imderside  of  their  beUy,  in  the  depths  of  the  ocean  ; 
on   the   sides,   and  often  on   the  upper  part  of   their 


CHAP.  II.  PRIMARY    DIVISIONS    OF    TESTACEA.  S/ 

bodies,  they  are  provided  with  processes  like  filaments  ; 
and  there  are  generally  two  very  short  tentacula,  at  the 
teimination  of  which  are  two  black  dots,  representing 
the  eyes  ;  in  this  respect  they  certainly  show  a  relation 
to  the  Gasteropoda,  but  then  their  respiratory  organs  are 
totally  different.  The  Nudihranchia,  in  short,  as  their 
name  implies,  have  these  organs  arranged  on  the  upper 
part  of  their  body,  in  the  form  of  a  rosette,  so  as 
exactly  to  resemble  a  bunch  of  vine  leaves,  whose  stalks 
form  a  common  centre.  One,  out  of  the  three  great 
characters  of  the  typical  Testacea,  is  yet  retained,  —  for 
the  animal  crawls  upon  its  belly;  but  has  lost  the  other 
two,  —  since  they  have  neither  a  distinct  head  nor  shell. 
The  tritons  and^  dories  have  the  additional  power  of 
swimming  and  crawling  on  the  surface  of  the  sea,  with 
their  foot  uppermost  :  in  the  former  case,  they  are  pro- 
pelled both  by  their  branchia  and  the  thin  sides  of  their 
body,  which  act  in  the  manner  of  fins. 

(SS.^   Our  next  group  is  composed  of  those  simply 
constructed  Testacea,  which  represent  the  Acrita  in  this 
class,   and  which  have  hitherto  been   arranged  among 
that  heterogeneous  assemblage  of  animals,  named  Intes- 
tina  by  Cuvier.      Having  now  arrived  at  the  most   re- 
mote limits  of  the  Testacea,  we  find,  in  the  order  before 
us,  nothing  more   than   faint  indications,   or,  in  other 
words,  the  elements,  of  that  organisation  which  belongs 
to   the   typical   tribes.       The  flattened  disk-like  form, 
indeed,  of  the  dories  and  the   tritons  is  fully  preserved 
in   the  Planarice,  and  even  in  some  of  the  Fasciolce  ; 
but  the  branchia,  hitherto  so  variable,  now  become  less 
and  less  apparent,  and  finally  disappear.     Some  of  these 
animals  inhabit  the  water,   but   others  are  internal  or 
external  parasites ;    and  this  change  of  habit  takes  place 
in  groups  so  intimately  connected   in  all  other  respects, 
that  we  become  convinced  of  the  propriety  of  retaining 
them  in  one  and  the  same  assemblage.     Hence,  without 
venturing  to  determine  the  precise  limits  of  the  animals 
which  really  belong  to  this  class,  we  feel  no  hesitation  in 
considering  a  large  portion  of  Cuvier's  Parexchymata, 

D    3 


38  SHELLS    AXD    SHELL-FISH.  PART  I. 

or  intestinal  worms,  as  truly  belonging  to  this  class. 
Our  reasons  for  this  will  be  again  adverted  to.  At 
present,  it  will  be  sufficient  to  state,  that  these  animals 
are  totally  distinct  from  the  true  Vermes,  where  the 
body  is  composed  of  articulations  more  or  less  developed, 
and  which  consequently  form  the  corresponding  group 
in  the  annulose  circle.  Nearly  all  of  these  imperfect 
and  obscurely  known  animals,  however,  partake  of 
the  general  character  of  the  Testacea,  in  crawling  or 
adhering  by  their  belly,  beneath  which,  —  as  in  the 
Fasciolce,  —  there  are  cup-shaped  disks,  or  suckers. 
Analogous,  in  every  respect,  to  these,  are  the  arms  of 
the  next  tribe. 

(34.)   In   this  manner,   then,   are  we  conducted  to 
the  fifth   and   last  tribe  of   the    testaceous   Mollusca, 
—  namely,    the   Cephalopoda,    or     cuttlefish.       But 
this  is   done   by   the  intervention  of  a   group  of  ani- 
mals, almost  as    simple    in    their  organisation    as   the 
intestinal  tribe    last    mentioned.     Some  of  the  Ptero- 
poda,  in  fact,  like  the  Parenchymata,  are  without  head, 
branchia,  eyes,  or  any  external  members  ;  even  the  fin, 
so  universal   among   the  Firolce,    is  wanting   in   such 
genera  as    Timorenia  and  Monojjliora  :    but  these,  or 
any  of  the  Hetei'opoda,   are  not  the  animals  to  which 
we  must  look  for  the  typical  characters  of  the   group 
before  us.     The  types  of  the  Cephalopoda,  in  fact,  are 
the   most  highly   organised,   and,   therefore,    the  most 
perfect,  of  all  the  Testacea.     The  appearance  of  these 
animals    is    strange     and    grotesque    in    the    extreme. 
Their  body  is  soft  and  pulpy,  having  the  limbs    ar- 
ranged in  a  circle  round  the  mouth  ;  these  limbs  per- 
form all  the  offices  of  feet,    arms,   and   tentacula,  and, 
in  many  genera,  they  are  used  also  as  fins.     The  head, 
which,  in  all  the  other  Testacea,  is  either  wanting  or 
but  slightly  developed,  is  here  large  and  conspicuous  ; 
while  the  eyes  are  so  clear  and  distinct,  that  they  re- 
semble those  of  a  vertebrated  animal ;  the  mouth,  from 
the  arrangement  of  the   limbs,   or,   as   we   shall   term 
them,  the  arms,  is  consequently  in  the  centre,  like  that 


CHAP.  II.  THE    CEPHALOPODA.  3Q 

of  a  radiated   animal ;  and  the  sides  of  the   body  are 
either  slightly  dilated  into  a  distinct  fin-shaped  mem- 
brane, or  are  so  thin  that  it  can  be  vised  for  the  same 
purpose.      In  size,  the  cuttlefish  are  by  far  the  largest 
of  all   the  testaceous  Mollusca ;  they  are,    indeed,   the 
giants  of  invertebrated  animals  ;   for,  if  the  accounts  of 
the  old   Indian  voyagers   are   true,   there   are   some  of 
such  enormous   dimensions,    that   they  seize   upon  the 
divers,  entangle  them  in  the  folds  of  their  serpent-like 
arms,  and  finally  devour  them.     These  stories  are,  no 
doubt,  exaggerated ;   but  we  have,  ourselves,  seen  many 
of  such  a  size,  caught  on  the  shores  of  Sicily,  that  two 
would  be  a  good  load, —  their  arms  being  as  thick  as 
those  of  a  man.     Most  of  these  animals  now  in  exist- 
ence are  naked;  but  in  the  former  aeras  of  the  world, 
there   appears,  unquestionably,    to    have  been  a  most 
numerous  and  gigantic  race,  which  had  a  part  of  their 
body  protected  by  a   spiral  shell,  rolled  in  the  form  of 
a  disk.     Ancient  revolutions   of   our    globe,    however, 
have  swept  away  nearly  the  whole  of  these  testaceous 
monsters,    leaving   in    the    Nautilus    almost    the   only 
genus  hitherto  found  in  a  recent  state.     It  is  among 
the  existing  genera  that  we  find  a  horny  or  calcareous 
plate,  which  supports  the  body,   and  is  altogether  in- 
ternal.    This,  as  before  remarked,  is  the  first  indication 
of  the  vertebrated  structure  among  molluscous  animals  ; 
and  hence,    nearly  all   zoologists   place    these    animals 
immediately  in  junction  with  the  Vertehrata  :   or  what 
is  the  same  thing,  consider  them  the  last  in  the  series 
of  the  Mollusca.     It  thus  appears,  on  a  general  view  of 
the  whole  of  the  testaceous  Mollusca,  that  they  may  be 
thus  concisely  described  :  — The  typical  and  sub-typical 
divisions  crawl,  and  are  covered  with  calcareous  shells ; 
of   which  the   first   is  univalve,   and   generally  spiral, 
while  that  of  the  other   is  bivalve  and  simple.     The 
aberrant   group,    on   the  contrary,  have   no  calcareous 
covering,  but  are  externally  naked,  and  they  have  the 
faculty  of  swimming  added  to  that  of  crawling.     Thus, 
we  cannot  but  adm.ire  the  simplicity  and  beauty  of  the 

D  4 


40  SHELLS    AND    SHELL-FISH.  PART  I. 

distinctions  which  nature  has  thus  stamped  upon  the 
primary  groups^  infinitely  diversified  as  they  are  in  all 
other  respects. 

(35.)  Our  next  object  is,  to  show  upon  what  grounds 
our  conviction  rests,  that  these  orders  form  a  circular 
group,  more  or  less  perfect.      It  is  hardly  necessary  to 
apprise  the  zoologist,  that  in  this  class  of  animals,  above 
all  others,  the  effects  of  those  revolutions  in  our  globe, 
which  have  nearly  exterminated  so  many  races  of  animals, 
are  most  apparent.      It  appears,  at  first,  difficult  to  say 
whether    this    destruction    has    been    most    extensive 
among  those  whose  hard  vestiges  yet  remain  in  a  fossil 
state,  or  among  such  as,  being  entirely  soft,  have  alto- 
gether  disappeared,  and   "  left  not  a  wreck  behind." 
Our  own  opinion,  however,  is  decidedly  in  favour  of 
the  latter  supposition.     Four  fifths  of  the   testaceous 
Cephalopoda  have  certainly  disappeared ;  yet  their  shelly 
portions,  abounding  in  incalculable  quantities  in  all  the 
older  formations,  are  yet  sufficient,  with  the  aid  of  the 
few  species  now  existing,  to  give  us  some  general  idea 
of  the  chain  of  continuity  :  but,  among  the  Nudihran- 
chia  and  the  Branchiopoda,  whole  families  seem  to  have 
disappeared :   such  of  the  latter,  indeed,  as  possessed  a 
hard  covering  may  be  judged   of  by  their  shells;    but 
in  what  way  their  union  was  effected  with  the  existing 
races  of  Dithyra  it   is  altogether  impossible  to  judge. 
The  Nndibranchia,  again,  are  allowed  by  all  naturalists 
to  constitute  a  distinct  tribe  ;  and  yet  it  does  not  con- 
tain more  individuals,  or  a  greater  diversity  of  structure, 
than  may  be  met  with  in  any  one  of  the  numerous 
families  of  the  gastropod  Testacea.     Now,  it  must  be 
remembered   that    these   are  all   soft,   and   often    sub- 
gelatinous,  animals,  without  any  hard  or  durable  parts 
whatsoever  ;   so  that  all  that  have  only  existed  in  former 
periods  of  our  globe,  have  been  exterminated  both  in 
life  and  substance,  no  indication  whatever  remaining 
that    they  ever    had  existence.      Upon   what  ground, 
then,  it  may  be  asked,  do  we  take  for  granted  that  they 
have  ever  been  among  the  things  that  were  ?  and  what 


CHAP.  II.  ON    EXTINCT    ANIMALS.  41 

reason  is  there  to  suppose  any  one  has  heen  abstracted 
from  the  living  races  ?  To  this  we  would  simply  re- 
ply^  that  such  a  conclusion  is  home  out  by  every  prin- 
ciple of  analogical  reasoning.  Throughout  the  whole 
of  the  vertebrated  classes^  it  is  solely  in  groups  where 
congenial  forms  have  been  found  in  a  fossil  state  that 
we  find  the  gradations  in  the  living  series  broken  and 
interrupted.  Very  few  such  interruptions^  for  instance, 
occur  in  the  class  of  birds,  and  they  are  so  slight  as 
hardly  to  merit  such  a  term :  this  fact,  in  our  esti- 
mation, at  once  accounts  for  the  extreme  rarity  of  the 
remains  of  birds  in  a  fossil  state;  scarcely  any  having 
been  exterminated.  The  living  series  is,  consequently, 
almost  perfect.  Not  so,  however,  among  the  reptiles. 
In  that  class  there  is  an  entire  order  (the  Elaniosaures) 
which  has  been  so  absolutely  exterminated  that  .not  a 
living  example  remains ;  hence,  but  for  the  fossil  bones 
of  the  Ichthyosaurus,  Plesiosaurus,  &c.,  there  would  not 
merely  be  a  wide  and  violent  disruption  of  the  reptile 
series,  but  an  absolute  impossibility  of  forming  even  a 
rational  conjecture  as  to  its  course  ;  at  least,  in  that 
dissevered  portion  which  these  extinct  reptiles  actually 
fill  up.  But  we  will  bring  this  theory  more  home  to 
our  present  purpose.  There  is  no  circular  series  of  living 
Testacea,  wherein  is  found  every  modification  of  form 
necessary  for  unquestionable  connection,  more  perfect 
than  that  of  the  predaceous  shell-fish  {^Gasteropoda 
Zoophaga):  hence  the  extinct  fossil  species  are  not  only 
rare,  but  they  nearly  all  belong  to  genera  now  living,  and 
therefore  termed  recent.  Any  one  family  in  this  group, 
in  short,  contains  more  species  and  genera  than  are  now 
known  in.  the  entire  tribe  of  Nudihranchia,  or  in  the 
family  of  Branchiopoda.  What,  then,  are  the  legitimate 
deductions  from  these  facts  ?  We  must  take  our  choice 
of  these  two :  —  Either  we  are  to  suppose  that  Nature  at 
first  made  these  latter  groups  as  imperfect  as  they  now 
are,  while  all  others,  abundant  in  recent  species  and 
forms,  are  perfect ;  or  that  she  has  removed  from  the 
creation  most  of  those  links  which  would  fill  up  the 


42  SHELLS    AND    SHELL-FISH.  PART  I. 

intervals  between  the  existing  races^  and  which^  were 
they  now  living,  would  render  all  her  groups  equally 
perfect.  All  analogy,  drawn  from  theory  or  from  facts, 
compels  us  to  embrace  this  latter  conclusion.  Perfec- 
tion in  all  His  works  is  one  of  the  attributes  of  the 
Creator;  it  is  therefore  clear  that  nothing  imperfect 
could  have  entered  into  the  plan  of  the  creation. 

{36.)  An  attentive  consideration  of  the  vertebrated 
classes  of  animals,  both  collectively  and  separately,  will 
convince  the  philosophic  inquirer,  that  in  every  instance 
nature  begins,  as  it  were,  from  a  small  rudimentary 
group,  —  a  point,  so  to  speak,  in  existence,  —  which 
seems  to  contain  such  animals  as  have  the  very  least 
affinity  to  those  which,  standing  at  the  head,  exhibit 
the  typical  structure  ;  they  possess  only  the  rudiments 
of  the  perfection  to  which  they  gradually,  but  ulti- 
mately, lead ;  and  their  structure  is  often  so  exceed- 
ingly simple,  that,  in  such  as  may  be  termed  the  germ, 
even  these  rudiments  are  scarcely  perceptible.  One  such, 
or  at  most  two,  are  all  we  can  expect  to  find.  Hence 
it  follows,  that  such  imperfectly  formed  beings,  although 
found  in  every  large  division  of  animals,  must  neces- 
sarily possess  a  strong  resemblance  to  each  other ;  al- 
though, in  reality,  they  belong  to  classes  widely  distinct, 
when  we  trace  them  up  to  their  full  developement. 
This  theory,  although  in  some  respects  not  new,  —  for  it 
has  been  tacitly  or  indirectly  admitted  in  a  general  way, 
—  has  never  received  that  attention  it  deserves.  It  has 
consequently  resulted,  that  nearly  all  those  authors  who 
overlook  the  important  differences  between  analogy  and 
affinity,  have  naturally  supposed  these  rudimentary 
animals,  as  they  may  be  called,  were  closely  connected 
to  each  other  hy  affinity,  and  have  accordingly  classed 
them  as  such.  This  seems  to  be  the  true  cause  why  we 
have  such  a  heterogeneous  assemblage  of  animals  under 
Cuvier's  class  of  Intcstina,  and  even  in  those  of  Mac- 
Leay's  Acrita  and  Vermes.  They  agree,  indeed,  in  one 
respect,  —  that  is,  of  being  the  most  simple  of  all  others 
in   structure ;  but  this  is   altogether   more   a   negative 


CHAP.  II.        OX  RUDIMENTARY  TYPES.  4S 

than  a  positive  character,  and  altogether  fails  of  that 
accuracy,  to  he  desired.  Besides,  it  is  quite  evident, 
that,  if  the  several  threads  of  affinity — collected  together 
in  the  above-mentioned  groups  —  had  been  followed 
up,  each  would  have  been  found  leading  to  totally  dif- 
ferent divisions  of  the  animal  kingdom.  The  Acrita, 
in  fact,  as  at  present  constructed,  is  such  an  ill-defined 
group,  that  some  writers  think  they  are  bound  to  bring 
"within  its  limits  the  Medusas,  and  many  of  the  most 
perfect  radiated  animals  ;  so  that,  if  this  is  allowable, 
there  is  no  reason  whatever  for  excluding  the  annulose 
Vermes,  the  cephalopodous  Foraminata,  and  the  mol- 
luscous Parenchymata.  It  may  be  thought  somewhat 
premature  to  state  these  objections,  seeing  that  we  have 
not  yet  attempted  to  substitute  any  other  arrangement 
of  the  Acrita  *  for  that  which  we  hold  to  be  a  false  one, 
although  proposed  by  the  very  founder  of  the  class.  But 
we  are  all  aware,  that  the  perception  of  an  error,  and 
the  power  of  rectifying  it,  are  not  inseparable.  Our 
researches  may  have  proceeded  quite  far  enough  to 
satisfy  us  on  the  former,  and  yet  may  not  have  extended, 
or  have  been  sufficiently  matured,  to  accomplish  the 
latter.  It  is  precisely  in  this  predicament  that  we  now 
stand.  Our  researches  in  the  true  Acrita,  the  Radiata, 
and  the  Annulosa,  —  have  advanced  sufficiently  far  to 
convince  us  of  the  fundamental  truth  of  what  we  have 
just  advanced.  The  subject,  however,  is  of  such  vast 
importance  to  the  first  principles  of  natural  arrange- 
ment, that  we  may  well  devote  to  it  a  few  additional 
remarks. 

(37.)  If  we  look  to  the  vertebrated  circle  of  animals, 
■we  find  that  many  of  the  amphibians  are  the  most 
simply  constructed  of  all  the  Vertehrata  ;  the  Amphiuma 
are  worm-like  salamanders,  having  the  body  excessively 

*  We  trust  this  investigation  may  be  taken  up  by  the  only  naturalist 
of  this  country  who  has  devoted  himself  to  the  study  of  the  soft  Mollusca, 
and  from  whose  talents,  experience,  and  zeal,  we  may  expect  so  much  — 
Dr.  Johnson.  It  is  a  serious  loss  and  inconvenience  to  science,  that  the 
numerous  and  truly  valuable  memoirs  of  this  accomplished  malacologist 
are  now  scattered  in  periodicals  and  magazines,  almost  hid  in  a  mass  of 
temporary  and  trivial  articles. 


4-4  SHELLS    AND    SHELL-FISH.  PART  I. 

lengthened,  and  the  legs  and  feet  so  small  as  to  be  rudi- 
mentary ;  while  the  Ccecilia  have  neither  feet  nor  bran- 
chia,  and  sometimes  are  without  eyes.  This  group, 
therefore,  among  the  Vertebrata,  is  precisely  the  sort  of 
point  or  nucleus  from  which  diverge  two  distinct  series 
of  animals  :  the  one  leads  to  the  serpents,  or  reptiles  ; 
the  other  branches  out,  in  an  opposite  direction,  to  the 
fishes ;  but  both  these  ultimately  meet  in  the  ostrich, 
which  exhibits  a  union  of  the  bird  and  the  quadruped.' 
Each  of  the  five  divisions  of  the  vertebrated  circle  afford 
parallel  instances  ;  so  that  we  invariably  find  the  most 
aberrant  group  is  always  that  which  is  the  least  or- 
ganised ;  just  as  is  the  class  ^cnto  in  the  whole  animal 
kingdom.  The  annulose  Vermes,  as  the  tape-worms, 
and  other  intestinal  creatures  stiU  more  simple,  forming 
the  Tcenioides  of  Cuvier,  are,  in  the  annulose  circle, 
precisely  what  the  amphibians  become  in  the  Vertebrata, 
They  exhibit  the  first  simple  outlines  /3f  that  structure 
which  terminates  in  the  painted  butterfly  and  the  sa- 
gacious bee  ;  and,  when  nature  has  reached  these  points 
of  perfection,  she  returns,  by  slow  degrees,  through  the 
Annelides,  or  red-blooded  worms,  to  the  same  point, 
although  by  a  different  route.  Such,  also,  will  be 
found  her  course  in  the  testaceous  class.  The  Paren- 
chymata,  or  parasitic  Mollusca,  may  be  considered  the 
first  indistinct  and  incipient  developement  of  the  Tes- 
tacea,  —  the  point  from  which  nature  diverges  towards 
the  phytophagous  gastropods  on  one  side,  and  to  the  car- 
nivorous gastropods  on  the  other,  until  both  these  series 
meet  together,  and  form  a  perfect  circle  in  the  family 
of  Turhklce.  It  will  subsequently  appear  that  this  re- 
markable principle  of  variation  is  not  merely  confined 
to  the  first  great  circle  formed  by  the  Testacea  ;  it  is 
abundantly  evident  in  its  primary  divisions — nay,  in 
some  instances,  even  in  its  families.  Among  the  Ce- 
phalopoda it  is  particularly  strong.  All  waiters  who 
have  mentioned  the  Foraminifera,  so  admirably  and 
beautifully  investigated  by  D'Orbigny,  hesitate  not  to 
place  these  microscopic  atoms  in  that  order,  although  it 


CHAP.  II.        ON  THE  TYPES  OF  ACRITA.  45 

contains  the  most  perfect  Mollusca  in  existence.  And 
yet  the  organisation  of  these  beings  is  so  very  simple, 
that,  if  no  regard  be  paid  to  the  difference  of  analogy 
and  affinity,  they  might  be  placed  next  to  the  animalcule? 
in  the  class  Acrita.  The  chitons  among  our  Gasteropoda, 
and  the  genus  Chelisoma  in  the  circle  of  the  Dithyra, 
are  further  instances  :  both  are  the  most  simple  and 
slightly  organised  of  their  separate  groups  ;  and  both, 
in  this  respect,  as  well  as  in  the  shape  of  their  bodies, 
are  prototypes  of  the  PlanaridcB  and  Fasciolce,  among 
the  parasitic  Testacea.  But  the  universally  confessed 
affinities  of  the  naked  slugs  to  the  testaceous  snails  brings 
this  theory  home  to  the  personal  cognisance  of  every 
naturalist.  Some  of  these  creatures  are  so  small,  ge- 
latinous, and  so  little  organised,  that,  but  for  their  in- 
disputable and  immediate  affinity  with  the  beautiful 
land  shells  of  the  Helix  race,  no  one  would  think  of 
placing  them  in  the  same  order,  much  less  in  the  same 
family  ;  and  yet  every  zoologist  sees  that  such  is  their 
natural  situation.  Hence  these  naked  slugs  become 
nothing  more  than  prototypes  of  the  PlanaricB  and 
Fascioltp ;  related,  ilideed,  to  them  by  analogy,  but 
without  any  connection  whatever  in  regard  to  affinity. 
The  extraordinary  genus  Herpa,  one  of  the  splendid 
discoveries  of  Guilding  (which  will  be  subsequently 
noticed),  carries  this  analogical  resemblance  to  the  highest 
pitch  ;  so  that,  but  for  the  discriminating  acumen  of 
that  profound  observer,  we  should  have  been  tempted, 
without  seeing  the  animal,  to  consider  it  was  an  actual 
type  of  Planaria,  in  the  disguise,  only,  of  a  Limax.  On 
these,  and  numerous  other  similar  facts  resulting  from 
the  analysis  of  this  class,  we  hesitate  not  to  place  a  por- 
tion of  Cuvier's  intestinal  worms  as  the  most  aberrant 
order  of  the  testaceous  Mollusca.  We  wish  to  follow 
nature,  and  nature  only  ;  perfectly  satisfied,  from  past 
experience,  that,  however  various  and  conflicting  may 
be  the  comments  of  her  interpreters,  she  has  pursued  but 
one  course,  and  but  one  plan,  in  her  system  of  animal 
variation. 


46  SHELLS    AND    SHELL-FISH.  PART  I. 

(38.)  We  may  noAv'^  commence  a  rapid  survey  of 
the  course  by  which  the  class  before  us  resolves  itself 
into  one  great  circle,  the  furtner  details  of  which  will 
be  noticed  under  the  several  chapters  devoted  to  the 
chief  divisions.  We  have  already  expressed  our  con- 
viction that  the  germs  of  the  Testacea  exist  among  the 
various  discordant  animals  comprising  Cuvier's  Paren- 
chymata,  but  it  is  by  no  means  clear  which  is  the  pre- 
cise point  where  the  very  first  indication  of  this  struc- 
ture is  seen ;  this  cannot  be  cleared  up  until  the  Acrita 
and  the  Radiata,  not  to  mention  the  annulose  Vermes, 
have  been  sufficiently  analysed.  Without  speculating, 
therefore,  on  the  probability  or  possibility  of  such 
genera  as  Echinorynchus  and  Herula  being  the  rudi- 
mentary type,  we  may  safely  point  to  the  Tremadotes 
of  Rudolphi,  and  the,  whole  of  the  second  family  of 
Cuvier's  Parenchymata,  as  containing  the  vermiform  or 
most  aberrant  types  of  the  class  before  us.  These,  in 
fact,  are  nothing  more,  in  one  sense,  than  naked  gas- 
teropod  Mollusca,  crawling  upon  their  bellies,  or  ad- 
hering by  means  of  cup-shaped  suckers,  which  are 
analogous  to,  and  perform  the  same  office  as,  the  single 
disk  of  the  more  perfect  testaceous  gastropods.  Some 
of  these,  like  the  FasciolcB  of  Linnaeus,  are  feeders  on 
the  internal  parts  of  animals,  and  adhere,  by  means  of 
these  suckers,  to  the  viscera  of  quadrupeds,  birds,  and 
fish  ;  others,  as  Cyclocotyles  of  Otto,  are  external  para- 
sites ;  while  the  true  PlanaridcE  are  entirely  free^  and 
swim  about  in  the  water.  Now,  it  is  from  these 
animals  that  nature  throws  out,  as  it  were,  two  lateral 
branches.  One  of  these,  emanating  from  the  Planaridce, 
conducts  us,  in  the  most  beautiful  and  graduated  man- 
ner, to  the  NudibranchUi ;  the  other,  departing  from 
the  Fasciola,  leads  us,  by  means  of  such  genera  as 
Menostoma  of  Blainville,  and  Hectocotylcs  of  Cuvier,  to 
the  no  less  vermiform  animals  among  the  Ftrolcp  and 
other  finless  Hetcropoda.  This  latter  branch,  however, 
we  shall  leave  after  this  indioation,  and  pursue  the  for- 
mer.   Commencing,  then,  with  the  Planarida',  we  see  a 


CHAP.  II.  GREAT    CIRCLE    OF    THE    TESTACEA.  47 

family  as  much  diversified  as  any  of  the  naked  Testacea, 
but  which,  at  present,  remains  almost  as  a  genus.  In 
it  are  found  representations  of  nearly  all  the  onisciform 
Molluscttj  as  Sigaretus,  Chelisoma,  Chelinotus,  Chiton, 
and  numerous  others  :  the  interesting  genus  Tristorna 
of  Cuvier,  contains  the  first  rudiments  of  branchia, — for 
such  do  we  consider  that  ^'  ramified  circular  vessel  in 
the  parenchyma  of  the  body/'  the  nature  of  which,  as 
that  learned  anatomist  conceives,  "  it  is  difficult  to 
determine."  *  This,  together  with  the  many  beautiful 
and  interesting  forms  discovered  and  figured  by  Riip- 
pell,  establishes  the  union  of  the  PlanaridcB  and  the 
DoridcE  —  in  other  words,  the  two  orders  of  Parenchy- 
wm^a  and  Nudihranclua — in  the  most  perfect  manner. 
^Ve  pass,  then,  from  these  latter,  to  the  Branchiopoda,  the 
first  tribe  in  the  order  of  bivalves.  From  this  point  our 
course  is  plain :  Anomia  connects  them  with  the  Ostrcea 
and  other  Dithyra  without  siphons  ;  while  these  latter 
are  connected  to  the  more  typical  bivalves,  where  these 
organs  are  fully  developed,  by  means  of  Chama  and 
Hippopus.  We  quit  the  perfect  bivalves  for  such  as 
are  tubular,  and  hence  almost  univalve  shells,  through 
the  Myadce  and  Solenidcp,  and  thus  reach  the  Teredince. 
By  this  latter  family,  the  path  is  smoothed  to  the 
terminal  series  of  the  Dithyi'a,  —  namely,  the  Tuhiili- 
hranchia  of  Cuvier, — where  we  have  the  singular  union 
of  a  gastropod  mollusk  inhabiting  a  tubular  shell. 
The  two  typical  orders  being  thus  united,  we  enter^  at 
once,  among  the  spiral  or  testaceous  Ga^Ye/'opocfa,  —  that 
group,  in  short,  which  stands  at  the  head  of  the  entire 
class.  Beginning  with  the  Scutihranchia  or  Patellides, 
as  the  least  organised  of  these  univalve  animals,  we  see  a 
gradual  developementof  the  spire  take  place  in  the  Halio- 
tidce,  Trochidce,  and  HelicidcB ;  until,  in  the  Tiirhidce, 
we  have  a  union  of  the  phytophagous  and  the  zoophagous 
gastropods.  The  old  genera  of  Melania  in  one,  and 
Cerithium  in  the  other,  effects  this  union,  and  conducts 
us  at  once  to  the  StromhidcFy  MuricidcB,  and,  finally,  to 

*  Griff.  Cuv.  xii.  473. 


48  SHELLS    AND    SHELL-FISH.  PART  I. 

the  Volutida.  The  transition  from  these  to  the  CyprmdcB 
is  no  less  clear  than  that  from  the  Cyprceidce  to  the  BuUcBj 
—  the  latter  being  the  most  perfect  of  the  TectihruncMa. 
In  some  of  these  half  naked  gastropods,   the  foot-like 
disk  of  the  belly  is  reduced  to  very  small  dimensions, 
while  the  two  lobes  of  the  mantle   become  so   dilated 
that  they  are  used  as  fins.     In  this  manner  does  nature 
leave  the  Gasteropoda,  and  unites  them  to  the  swim- 
ming order  of  Cephalopoda, — the  first  tribe  of  which  is 
the  Pteropoda.  The  straight  cylindrical  case  of  some  of 
these  singular  animals,  few  in  number,  but  highly  in- 
teresting, prepares  us  for  that  extinct  tribe  of  cuttle- 
fish of  which  the  fossil  Belemnites,  in  all  probability, 
formed  the  type :  from  these  to  the  spiral  Cephalopoda, 
the  passage  is   so   easy,  that  it  can  be  traced  by  the 
shells  alone;  and  then,  with  the  assistance  of  Argonauta 
and  C{irinaria,  we  at  once  reach  the  Heteropoda.     The 
affinity    between    some    of    these    simply    constructed 
animals  and  the  aberrant  Parenchymata  has    already 
been   intimated.     Thus   we  find   that  the  two  lateral 
series  which  branch  off  from  the  Planaridce  meet  toge- 
ther in   the  Turhidce,  and   complete  the   circle  of  the 
whole  class. 

{39-^  Ii'i  thus  tracing  the  course  of  the  circle  of  the 
Testacea,  the  zoologist,  versed  in  the  circular  theory, 
will  perceive  we  have  taken  no  notice  of  the  most  aber- 
rant groups  in  each  order, — and  this,  because  it  would 
have  incumbered,  without  necessity,  the  simple  ex- 
position of  the  union  of  the  orders  themselves.  He  will 
also  be  aware  that  it  is  by  these  particular  groups  that 
each  order  forms  a  circle  of  itself.  This  important  pro- 
perty will,  of  course,  be  adverted  to  when  we  come  to 
treat  of  each  order  separately.  In  the  mean  time,  we 
shall  now  compare  the  orders  of  the  Testacea  with  such 
other  groups  of  the  animal  kingdom  as  appear  calculated 
to  render  their  analogies  more  comprehensible  to  the 
ordinary  reader.  Our  first  comparison  will  consequently 
be  with  the  vertebrated  anhnals. 


CHAP.    II.  ANALOGIES    OF    THE    TESTACEA.  49 

Analogies  of  the  Testacea  to  the  Vertebrata. 

:^      Orders  of  the  Testacea.  Circ\e  oC  the  rerfebrata. 

Gasteropoda.  Qiiaorupeus. 

DiTllYRi.  JilRDS. 

NlJDlBRANCHIA.  REPTILES. 

Parenchvmata.  A:mphibians. 

Cephalopoda.  Fishes. 

(40.)  The  reader  will  bear  in  mind  that,  hitherto,  we 
have  spoken  of  relations  of  affinity ;  but  our  present 
business  is  with  analogies,  or  mutual  representations. 
Setting  aside,  therefore,  all  we  have  already  advanced, 
we  accordingly  find  that  the  best  modern  zoologists  place 
the  Dithgra,  or  bivalve  shell-fish,  close  to  the  Gaste- 
ropoda, or  univalves,  upon  the  same  principle  as  the 
birds,  in  the  other  column,  follow  the  quadrupeds. 
This  arrangement,  at  the  very  first,  seems  to  carry  with 
it  an  appearance  of  being  natural,  because  we  thus  find 
that  both  the  Dithgra  and  the  Ai'es  are  the  sub- typical 
divisions  of  their  own  circles.  But  this  parallelism, 
although  highly  satisfactory,  is  not  of  itself  sufficient ; 
we  must  look  further,  and  inquire  whether  these  groups 
actually  agree  in  any  particular  circumstance  of  struc- 
ture, common  to  both.  Now,  every  one  knows  that, 
among  the  many  things  in  which  quadrupeds  differ 
from  birds,  their  mode  of  feeding  is  altogether  dissi- 
milar. Quadrupeds  are  provided  with  jaws  bearing 
teeth,  with  which  the  food  is  masticated  before  it  enters 
the  stomach :  birds,  on  the  contrary,  have  the  jaws 
dilated  into  a  snout-shaped  bill,  and  teeth  are  alto- 
gether wanting.  The  rapacious  birds  (Raptores),  in- 
deed, which  typify  the  quadrupeds,  may  be  said,  in  some 
degree,  to  masticate  their  food  ;  but  by  all  others  it  is 
sucked  into  the  mouth,  the  effects  of  mastication  being 
supplied  by  the  stomach.  If  we  inquire  into  the  modes 
in  which  the  typical  Gasteropoda  and  the  Dithyra  take 
their  food,  we  find  that  it  is  precisely  conformable  to  the 
above  variation.  The  most  typical  of  the  spiral  shell- 
fish (^Gasteropoda),  like  quadrupeds,  are  provided  with 
fleshy  lips  and  corneous  jaws,  varied,  as  M.  Cuvier  truly 
observes,  into  numerous  modifications  ;  while  in  many 
genera  (on  the  same  authority),  the  inside  of  the  cheeks 

E 


50  SHELLS    AND    SHELL-FISH.  PART  1. 

are  provided  with  reflected  teeth^  to  aid  deglutition. 
On  turning  to  the  Dithyra,  however^  we  find  a  totally 
different  structure  :  the  mouth  has  neither  lips^  jaws^ 
nor  teeth,  but  is  "  a  simple  aperture"  entering  into  the 
stomach ;  the  food,  in  short,  is  sucked  in,  and  is 
swallowed  entire,  as  it  is  by  birds  :  so  that,  strange  as 
it  may  appear,  the  two  most  perfect  groups  of  the 
testaceous  Mollusca  exhibit,  generally  speaking,  the 
same  mode  of  feeding  as  the  two  most  perfect  groups 
of  vertebrated  animals.  It  seems  hardly  necessary  to 
strengthen  analogies  so  beautiful ;  yet  we  cannot  omit, 
in  this  place,  that  there  are  not  wanting  indications,  even 
in  the  structure  of  the  bivalve  shell-fish,  to  remind  us  of 
the  peculiar,  character  of  birds  :  in  these  latter,  the  sides 
of  the  body  are  enveloped  by  two  broad  and  expansive 
wings  ;  in  like  manner  is  the  body  of  an  acephalous 
bivalve  enveloped  on  its  sides  by  the  ample  folds  of  its 
cloak  or  mantle.  Yet  neither  of  these  appendages  occur 
among  the  typical  quadrupeds  and  the  typical  gastro- 
pods.* But  it  is  time  to  pass  on  to  the  Nudibranchia 
and  the  reptiles.  Do  these  represent  each  other  .f*  and 
in  what  manner  ?  We  will  set  aside  that  forbidding 
appearance  which  these  reptile-looking  Mollusca  possess ; 
and  which  indicates,  at  first  sight,  some  analogy  to  the 
true  reptiles,  because  this  is  a  mere  m.atter  of  opinion  : 
not  so,  however,  is  the  circumstance  that  both  these 
classes  crawl  upon  their  belly,  and  are  destitute  of  any 
limbs.  The  tritons,  in  fact,  have  no  real  feet ;  and 
the  serpents,  standing  at  the  head  of  the  ReptUia,  are 
eminently  distinguished  in  the  very  same  way.  The 
analogies  of  the  Parenchymata,  in  general,  have  been 
sufficiently  explained  ;  it  is,  therefore,  only  necessary 
to  observe  in  this  place,  that  the  Amphibia  are  the  most 
imperfect  of  the  vertebrated  animals,  just  as  the  Paren- 
chymata are  the  most  simply  constructed,  and  the  fur- 
thest removed  from  the  typical  Testacea.  Their  short, 
thick,  and  broad  form  reminds  us  again  of  the  onisci- 
form  type  of  annulose  animals.     We  have  now  only  to 

[*  Except  in  such  as  are  aberrant  in  their  ovv-n  circles,  as  the  Volutidce,  &c. 


CHAP.  II.  THE    TESTACEA    AND    ANNULOSA.  5\ 

compare  the  two  last  groups  in  our  table^  —  namely^  the 
Cephalopoda  and  the  true  fishes.  These  agree  in  con- 
taining the  largest  individuals  of  their  respective  circles, 

—  except,  indeed,  the  fish-quadrupeds,  or  whales.  Both 
swim  by  means  of  their  fins,  which  in  both  groups 
represent  the  arms  and  feet  of  other  animals  :  the  eyes 
of  both  are  almost  perfectly  the  same  :  the  old  natu- 
ralists, indeed,  who  were  more  led  by  general  appear- 
ance than  by  anatomical  peculiarities,  considered  the 
cuttlefish  and  Loligo  as  true  fishes.  It  may,  therefore, 
safely  be  said,  that,  if  we  are  to  decide  which  division 
of  the  Testacea  bears  the  greatest  resemblance  to  fishes, 

—  whether  as  regarding  outward  form  or  internal  or- 
ganisation,— no  one  would  hesitate  to  name  the  Cepha- 
lopoda as  that  group. 

(41.)  In  further  confirmation  of  this  arrangement, 
we  will  take  a  slight  glance  at  the  classes  of  annulose 
animals  (which  are  to  form  the  next  volume  of  our 
series),  and  compare  them  with  those  of  the  Testacea. 
It  is  scarcely  necessary  to  dwell  upon  the  two  typical 
groups  of  each,  —  the  Gasteropoda  and  the  Ptilota, 
which  stand  as  the  pre-eminent ;  and  the  Aptera  and 
Dlthyra,  as  the  suh-typical  classes  :  when,  however, 
we  proceed  to  the  aberrant  groups,  we  find  the  analogies, 
as  in  all  other  instances,  much  stronger.  How  beauti- 
ful, for  instance,  do  the  Annelides,  or  red-blooded  worms, 
put  on  the  very  aspect  and  form  of  the  Nudibranchia  ; 
a  naturalist,  looking  to  the  outward  appearance  of  these 
creatures,  —  their  naked  body,  often  covered  with  tufts 
of  plumed  or  ramose  appendages,  assuming  sometimes 
the  likeness  of  horns,  filaments,  or  tentacula,  —  would 
even  entertain  a  suspicion  that  they  really  belonged  to 
the  same  class  of  animals.  No  wonder,  therefore, 
that  the  older  naturalists,  and  even  Linnaeus,  mixed 
them  together ;  since  the  circumstance  of  one  having 
red,  and  the  other  white,  blood,  was  not,  in  those  days, 
considered  a  matter  of  much  importance.  Now,  this 
analogy,  which  is  perhaps  one  of  the  most  striking  in 
the  whole  of  the  animal  creation,  is  highly  important 

E  2 


52  SHELLS    AND    SHELL-FISH.  PART  I. 

when  viewed  in  reference   to  any  doubts   which  may 
hang  over  this  group^  from  its  isolated  situation  on  one 
side  of  its  own  circle.      The  strong  analogy  between  the 
Parenchymata   and   the   annulose    Vermes  has   induced 
all   writers   to  blend   them   together^  even  up    to   this 
day  ;  the  one  being  the  most  imperfect  of  all  the  Tes- 
tacea,  as  the  other  is  of  the  Annulosa.     Passing  on  to 
the    relationship  between  the  cuttlefish    {Cephalopoda) 
and  the  barnacles  {Cin'ipeda),   we  are  struck  with  a 
resemblance  much  stronger   than  would    be  supposed 
to  result  from  a   mere  relation   of  analogy.      In  both 
these  tribes,  the  mouth  is  surrounded  by  long  slender 
arms,  employed  to  catch  their  prey  :  both  contain  ani- 
mals whose  softer  parts  are  protected  by  shells.     Never- 
theless the  Cirripedeshsive  no  more  to  do  with  MoUusca, 
than  the  latter  have  with  those   crabs,   which,  like  the 
genus  Cyclops,  are  naturally  enveloped  in  bivalve  shells. 
To  the  Radiata,  again,  the  analogy  of  these  tribes  is  no 
less  apparent ;  for,  as  both  have  the  organs  of  motion 
arranged  around,  or  rather  radiating  from,  their  mouth, 
which  thus  becomes  the  common  centre,  they  have,  to 
all  outward  appearance,  the  essential  characters  of  ra- 
diated mollusks. 

(42.)  Assembling  all  the  groups  thus  brought  into 
comparison  in  the  following  table,  we  shall  see,  at  one 
glance,  the  mutual  relations  they  present  in  their  com- 
ponent parts. 


Analogies  of  the  Test  acrovs  Mollusca  to  the  Annulosa. 

Analogical  Characters. 
"Typical,   the  most  hif;hly   organised;' 


Tribes  of  ,«      7     •     ? /-.i         j  Classes  of  the 

-r  „/^^,^  Analogical  Characters.  j.,  ,.  ;  ^ 

festacea.  ^  Annulosa. 


rTypical,   the  most  hif;hly   organised  ;T 
Gasteropoda.     <     head  distinct,  with  long  antennae  or  >Ptilota. 
t     tentacula.  j 

rHead  indistinct,  confounded  with  theT 
DiTHYRA.  -j     thorax,  or  altogether  wanting;  no>APTERA. 

C     antennte  or  tentacula.  J 

M.Tn,T,DAi«r'«ii     yCiskof  the  belly  flattened,  and  often  7  4^,„^,,„^, 
NUDIBRANCHIA.    ^     performing  the  olhcc  of  a  foot.  j  Annelides. 

TThe  most  simple  in  their  organisation,  1 
Parenchymata.  •<     naked,  and  crawl  upon  tiieir  belly  ;>  Vermes. 

C     no  perceptible  branchia.  j 

f  Mouth  surrounded  by  long  tentacula,^ 
Cbphalopoda.      <     or  arms  ;  soft  parts  of  the  body  ge- ^Cirripeoa. 

C.     ncrally  protected  by  a  shell.  j 


CHAP.  111.       THE  ORDER  GASTEROPODA.  $3 

So  singularly  do  the  Aptera  represent  the  Dithyra 
by  the  head  (as  in  spiders  and  scorpions)  being  con- 
founded with  the  trunk,  that  they  might  even,  without 
any  violation  of  propriety,  be  termed  acephalous  in- 
sects. But  we  presume  enough  has  now  been  said  on 
this  set  of  analogies,  to  satisfy  the  unprejudiced  reader. 
And  having  now  sufficiently  dwelt  upon  our  arrange- 
ment of  the  Testacea  as  a  class,  we  may  at  once  pro- 
ceed to  the  details  of  the  tribes  in  which  the  whole 
are  here  arranged. 


CHAP.   III. 

ON  THE  ORDER  OF  GASTEROPODA,  ITS  PRIMARY  DIVISIONS,  AND 
THE  CHARACTERS  AND  ANALOGIES  OF  THE  MlIRICIDjE  AND 
THE    TURBINELLID^. 

(43.)  The  gastropod  shell-fish,  as  we  have  already 
shown  in  the  preceding  pages,  stand  at  the  head  of  the 
testaceous  Mollusca,  —  a  station  which  both  Cuvier  and 
Lamarck  have  also  assigned  to  them.  This  has  now  been 
confirmed  by  the  theoretical  and  analogical  tests  with 
which  our  last  chapter  was  concluded.  Bnt  as  our  ar- 
rangement of  these  aninials  will  be  in  many  respects 
very  different  from  that  of  preceding  writers,  it  will  be 
proper,  before  submitting  its  details  to  the  reader,  that 
we  should  take  a  short  review  of  the  group  as  it  at  pre- 
sent stands  in  existing  systems. 

(44.)  On  referring  to  the  definitions  given  in  the 
Itegne  Animal  of  the  order  Gasteropoda*,  and  to  the 
animals  composing  it,  we  find  it  embraces  more  than 
nine  tenths  of  the  whole  of  the  Mollusca  inhabiting 
univalve  shells,  and  by  far  the  greater  part  of  such  as 
are  naked.  The  inevitable  consequence  of  thus  includ- 
ing a  multitude  of  groups,  differing  from  each  other  in 

*  Griffith's  Cuvier,  xii.  21. 
E    3 


54'  SHELLS    AND    SHELL-FISH.  FART  I. 

almost  every  thing,  has  been  this_,  —  that  the  reader  is 
at  a  loss  to  know  by  what  other  principle  they  are 
united,  even  according  to  the  system  of  the  learned  au- 
thor. Some  crawl  on  their  belly,  others  do  not ;  some 
have  shells,  others  none ;  many  have  a  distinct  head, 
but  many  have  not ;  the  eyes  are  present,  or  they  are 
wanting :  all  the  organs,  in  short,  of  respiration,  deglu- 
tition, and  reproduction,  are  admitted  to  vary  ;  and  this, 
in  such  an  extraordinary  manner,  and  in  species  so  ob- 
viously allied  to  each  other,  that  they  have  no  claim  to 
a  primary  consideration.  True  it  is,  that  all  these  ani- 
mals possess  an  aortic  heart ;  but  this,  properly  speak- 
ing, is  more  the  universal  character  of  the  testaceous 
Mollusca  as  a  class,  than  one  by  which  such  an  immense 
number  of  animals,  totally  different  in  all  other  respects, 
can  be  distinguished.  The  order,  as  it  noAv  stands,  may 
be  said  to  embrace  the  whole  of  the  Mollusca,  except  the 
Dithyra,  or  bivalves,  and  the  Cephalopoda,  or  cuttlefish. 
"  There  is.  no  doubt,  some  great  error,"  observes  jNJr. 
MacLeay,  "  yet  undetected  in  the  principles  upon  which 
we  are  accustomed  to  arrange  the  3Iollusca,  and  that 
we  shall  never  arrive  at  the  truth,  by  looking,  like  M.  de 
Blainville,  solely  to  the  position  and  structure  of  the 
organs  of  respiration ;  or,  like  M.  Cuvier,  to  the  method 
of  reproduction,  as  when  he  unites  the  Cyclohranches  to 
the  Acpphala  or  Dithyra. 

(45.)  Rejecting,  therefore,  all  those  animals  from  the 
true  gastropods,  which  have  neither  a  distinct  head,  as 
the  Tubulibranchia,  or  whose  branchia  are  naked,  as  in 
Doris,  we  shall  retain  an  assemblage  of  mollusks,  nearly 
all  of  which  are  furnished  with  univalve  shells*;  and 
whose  head,  distinguished  from  their  body,  is  provided 
with  tentacula  and  eyes ;  the  flattened  part  of  the  belly 
serving  them  as  a  foot.  Thus  restricted,  we  shall  find 
that  nearly  all  the  remaining  divisions  of  M.  Cuvier, 
under  certain  modifications,  indicate  so  many  natural 
groups.     It  is    clear,   however,   that  when   M.  Cuvier 

*  Excppt  in  Chiton,  where  the  valves  are  separate  and  dorsal  only,  and 
some  of  the  Tectibrancliia. 


CHAP.  III.  TRIBES    OF    THE    GASTEROPODA.  55 

places  such  genera  as  Planorhis  and  Ampullaria  in  two 
different  orders,  merely  on  account  of  a  difference  in  their 
organs  of  respiration,  he  falls  into  as  great  an  error  as 
that  he  has  elsewhere  committed  in  uniting  the  Cyclo- 
.hranchia  to  his  Acephala.  The  order  Piihnonaria,  there- 
fore, must  be  clearly  abolished.  This,  indeed,  has  been 
already  done  by  Lamarck,  whose  authority  on  all  ques- 
tions of  natural  affinity  must,  in  general,  be  regarded  as 
superior  to  that  of  Cuvier. 

(46.)  ^\^ith  the  foregoing  restrictions,  the  primary 
divisions  of  the  order  before  us  wuU  be  found  to  consist 
of  the  five  following  tribes:  —  1.  The  Zoophaga  of 
Lamarck,  or  the  carnivorous  shell-fish  (corresponding  to 
the  Pectinibranchia  Cuv.);  2.  The  Phytophaga  of  the 
same  author,  which  live  chiefly  on  vegetables,  as  the 
snails  and  slugs;  3.  The  Scutibranchia  Cuv.,  or  lim- 
pets ;  4.  The  Cyclobranchia  Cuv.,  or  chitons  ;  and,  5. 
The  Tectibranchia  Cuv.,  or  buUas,  whose  univalve 
shells,  where  they  exist,  are  all  hid  in  the  flesh  of  the 
animal,  while  their  mantle  is  dilated  into  two  fin-Hke 
lobes,  with  which  they  can  swim.  We  shall  now  state  a 
few  general  particulars  of  these  tribes,  and  then  proceed 
to  determine  their  analogies. 

(47.)  The  Zoophaga  are  the  most  pre-eminently 
typical  of  the  whole  of  the  testaceous  Mollusca  ;  and 
this  holds  good,  whether  we  regard  the  organisation  of 
the  animal,  or  the  symmetry  and  beauty  of  their  ex- 
ternal shell,  wdth  which,  in  every  instance,  they  are 
provided.  They  have  only  two  tentacula ;  and  the  eyes, 
which  are  always  conspicuous,  are  sometimes  (as  in  the 
Stromhid(E)  highly  developed-  The  edge  of  the  mantle 
is  almost  always  provided  with  a  siphon,  or  tube  for 
respiration,  and  by  which  the  animal  can  breathe  without 
protruding  its  head  and  foot  from  the  aperture  of  its 
shell :  this  siphon  is  protected  by  a  corresponding  canal, 
either  long  or  short,  at  the  base  of  its  habitation  ;  and  its 
presence,  in  all  these  Mollusca,  constitutes  one  of  their 
most  essential  characters.  The  mouth,  also,  is  very  re- 
markable, —  resembling  more  or  less,  as  Cuvier  well 

E    4 


56 


SHELI.S    AND    SHKLIi-FISIl.  PARTI. 


observes,  "an  elongated  proboscis.  Their  tongue/'  he 
continues,  "  is  armed  with  little  hooks,  which,  by  slow 
and  repeated  rubbings,  act  upon  the  hardest  bodies/' 
It  is  by  this  process  that  they  perforate,  with  the 
smoothness  and  precision  of  an  auger,  the  shells  of. 
other  animals,  which  they  then  destroy  and  suck  the 
juices  of.  The  sexes  are  always  separate;  and  the 
aperture  of  the  shell,  in  most  instances,  is  closed  by  an 
operculum.  The  various  modern  genera  formed  out 
of  the  Linna^an  Murex,  Biiccinum,  Conns,  Voluta,  &c., 
are  included  in  this  tribe,  the  shells  of  which  are 
always  spiral,  and  furnished  with  a  notch  or  emargin- 
ation  at  the  base. 

(48.)  The  Phytophaga,  as  the  name  implies,  are 
feeders  upon  plants ;  for  although  several,  like  the 
slugs,  will  devour  animal  substances,  they  more  habitu- 
ally live  upon  vegetables.  They  are,  besides,  eminently 
distinguished  from  the  carnivorous  race  by  two  cha- 
racters :  their  mouth  does  not  form  a  proboscis  ;  and  the 
aperture  of  their  shell  is  entire, — in  other  words,  without 
the  notch  or  canal  for  the  passage  of  the  siphon  (when 
it  exists),  so  universal  in  the  last  group.  In  all  but 
one  or  two  genera,  as  the  slugs  and  the  marine  Onchid^B, 
they  are  more  or  less  covered  with  shells,  which, 
in  however  small  a  degree,  are  always  spiral.  By  far 
the  greater  part  of  them  have  the  sexes  separate  ;  but  in 
regard  to  all  the  other  organs  connected  with  respiration, 
they  may  be  said  to  vary  in  every  possible  way, — a  clear 
proof  that  such  variations,  in  groups  naturally  and 
closely  allied,  cannot  be  taken  in  an  arbitrary  sense. 
Many  of  these  animals  have  their  branchia  as  in  the 
Zoophaya;  some  few,  as  Cyclostoma  and  Helicina,  even 
according  to  M.  Cuvier's  admission  (who  places  them, 
nevertheless,  with  his  Pectin  ibrajichia),  ''  have  instead  of 
gills,  a  vascular  network  covering  the  top  of  a  cavity 
that  is  otherwise  similar ;  and  they  respire,  like  the 
Limax,  the  natural  air."  The  whole  of  the  terrestrial 
slugs  and  snails,  again,  breathe  through  an  open  perfo- 
ration under   the  edge   of  the  reflected  mantle,  which 


CHAP.  III.  TRIBES    OF    THE    GASTEROPODA.  57 

they  can  dilate  or  contract  at  pleasure  :  hence  they 
have  no  gills,  "  but  merely  a  network  of  pulmonary 
vessels,  which  spread  over  the  parietes  and  the  roof  of 
their  respiratory  cavity."  The  tentacula,  in  such  as 
inhabit  fresh  water,  are  generally  only  two  ;  but  in  the 
land  and  amphibious  groups,  as  Helijo,  Ampidlaria,  Pla- 
norbis,  &c.,  they  are  four.  Their  food,  notwithstand- 
ing all  these  variations,  is  always  essentially  vegetable. 
Their  mouth  is  uniformly  the  same,  and  their  shell  is 
always  spiral ;  this  latter  circumstance,  it  should  be 
remembered,  carries  with  it  an  important  character  in 
the  form  of  their  body,  which  is  of  much  consequence, 
and  separates  them  from  the  next  tribe.  The  whole 
of  the  land  shells,  as  well  as  the  marine  families  of 
Neritinw,  Turbidce,  TrochidcE,  &c.,  are  comprised  in 
this  division ;  the  HaUotidcp,  or  ear-shells,  being  the 
connecting  link  to  the  next. 

(49.)  The  ScuTiBRANciiiA  have  the  same  system  of 
respiration,  according  to  Cuvier,  as  hh  PectinibrancMa ; 
but  they  differ  not  only  in  their  mode  of  reproduction, 
but  most  remarkably  in  the  form  of  their  body.  They 
are  all  attached  to  their  shelly  covering  by  an  amazing 
strong  muscle,  which  fills  the  centre,  and  gives  them 
such  an  adhesive  power,  that  they  affix  themselves  im- 
moveably  to  other  substances,  from  which  they  can 
only  be  separated  by  the  sudden  insertion  of  some  sharp 
instrument.  They  are,  in  fact,  affixed  Testacea ;  for 
although  the  animals  can  move  about,  they  cannot  live 
but  upon  a  substance  where  they  can  instantaneously 
fix  themselves.  In  their  internal  structure,  we  find  the 
heart,  according  to  Cuvier,  "  traversed  by  the  rectum, 
and  receiving  the  blood  from  two  auricles,  as  is  the  case 
in  the  greater  number  of  bivalves."  *  The  form  of 
the  shell  is  no  less  peculiar  ;  its  general  shape  is  that  of 
a  low,  broad-based  pyramid,  or,  if  viewed  inside,  of  a 
very  wide  but  shallow  funnel.  The  common  limpet, 
in  short,  appears  to  us  the  most  typical  of  the  whole  ; 

*  It  is  by  this  group,  in  fact,   as  will  subsequently  be    shown,  tliat  we 
consider  the  Gasteropoda  and  the  Di(/ii/ia  are  united. 


58  SHELLS    AND    SHELL-PISH.  PART   1. 

for  although  this  genus  has  heen  excluded  by  some 
writers,  and  separated  from  Fissurella,  Sec,  in  a  dis- 
tinct tribe,  yet  this  is  evidently  doing  a  violation  to 
nature.  None  of  the  genera  in  our  present  group  pos- 
sess spiral  shells ;  for  although  Haliotis  is  obviously 
intermediate  between  the  Phytophaga  and  the  Scuti- 
hranchia,  its  preponderating  character,  both  as  regards 
the  animal  and  the  shell,  appears  to  us  in  favour  of  its 
being  placed  as  the  last  of  the  turbinated  families,  rather 
than  as  the  first  of  the  present  group.  Thus  restricted, 
the  Scutihranchia  will  contain  Patella,  Siphonaria, 
Fissurella,  E7nargmula,  Parmophorus,  Capulis,  Sec, 
together  with  the  singular  genus  Hijiponyi-,  of  which 
we  shall  have  occasion  to  speak  hereafter.  Magilis 
and  Siliqiiaria  evidently  disturb  this  series,  yet  open  a 
direct  path  to  the  Dithyra,  or  bivalves. 

(50.)  The  Cyclobranchia,  according  to  Cuvier,  '^'have 
the  branchia  resembling  small  lamella,  or  little  pyra- 
mids, forming  a  cordon  more  or  less  complete  under  the 
borders  of  the  mantle,  very  nearly  the  same  as  the  In- 
ferohranchia,"  from  which,  however,  he  separates  them 
on  account  of  their  different  system  of  reproduction  : 
"  the  heart,"  he  continues,  "  does  not  embrace  the 
rectum,  but  its  situation  varies  ;  the  stomach  is  mem- 
branaceous, and  the  intestines  very  long."  The  only 
genera  placed  by  Cuvier  in  this  group,  are  Patella  and 
Chiton.  The  first,  however,  is  so  evidently  connected 
to  the  Scutihranchia  in  all  other  points  of  organisation, 
setting  aside  the  shell,  that  we  have  no  hesitation  in 
adopting  the  theory  of  Lamarck,  who  unites  the  genera 
Phyllidia  and  Diphyllidia  to  Chiton,  particularly  as  this 
arrangement  at  once  opens  a  direct  passage  to  the  Tcc- 
tihranchia.  The  shells  of  the  chitons,  which  thus 
become  the  types  of  the  Cyclobranchia,  are  boat-shaped 
and  multivalve,  the  valves  being  disposed  transversely 
upon  the  back  of  the  animal,  and  folding  over  each 
other  like  a  coat  of  mail. 

(51.)  TheTECTiBRANCHrA,to  which  we  are  conducted 
by  Lamarck,  form  a  most  natural  group.    It  is  peculiarly 


CHAP.  III.      TRIBES  OF  THE  GASTEROPODA.        59 

interesting^  because  it  contains  those  diverging  genera 
which  connect  it  not  only  with  the  chitons^  but  with 
the  Gasteropoda  on  one  side,  and  the  Cephalopoda,  on 
the  other.  They  may  be  described  as  thick,  fleshy, 
soft  mollusks,  generally  possessing  a  distinct  head 
furnished  with  a  pair  of  ear-shaped  tentacula,  and  with 
the  mantle  usually  dilated  into  two  lobes  resembling 
fins :  the  branchia  are  folliculated  on  the  right  side  or 
on  the  back,  and  are  generally  covered  by  a  small 
bulla-shaped  shell  concealed  in  the  folds  of  the  body. 
They  have  the  power  both  of  crawling  by  means  of  a 
narrow  disk  on  their  belly,  and  of  swimming  by  their 
fins.  JNIany  of  the  species  are  very  large,  and  when 
taken  out  of  the  water  they  appear  like  great  oval 
masses  of  flesh.  They  are  the  only  swimming  gas- 
tropods possessed  of  a  univalve  shell,  and  are  con- 
nected to  the  Cephalopoda  by  the  singular  genus  Gas- 
teropteron  Meek.,  which  thus  brings  us  at  once  to  the 
Pteropoda ;  while  the  connection  of  the  Bullce  to  the 
CypraidcR  is  obvious  to  every  one. 

(52.)  The  union  of  the  Phytophaga  and  the  Zoophaga, 
or  the  typical  divisions,  is  so  perfect,  that  the  only  ap- 
parent difliculty  seems  to  be  where  one  terminates  and 
the  other  begins  :  thus,  if  we  look  to  the  possession  of  a 
siphon  as  a  primary  distinction  of  the  Zoophaga,  we 
find  this  organ  fully  developed  in  the  sub-aquatic  genus 
Ampullaria,  which  is  nevertheless  so  closely  united  in 
its  other  characters  to  the  Phytophaga,  that  we  cannot 
separate  it  from  its  obvious  allies  :  the  mouth  of  the 
shell,  in  fact,  is  as  entire,  or  rather  as  destitute  of  any 
notch  or  canal,  as  that  of  the  garden  snail ;  while  PlO' 
naxis  and  Melanopsis,  both  of  which  are  most  inti- 
mately related  to  Melania,  have  a  deeply  notched 
aperture.  If  we  look  to  the  relations  afforded  by  the 
animals  themselves,  the  same  interchange  of  characters 
takes  place.  As  these  two  groups  follow  each  other  in 
afl5nity,  we  may  pass  on  to  the  HelicidcE,  or  land  snails, 
and  the  marine  Trochidce,  until  we  reach  the  Scuti- 
hranchia  by  means  of  such  genera  as  Trochella,  which 


60 


SHELLS    AND    SHELL-FISII.  PART   I. 


unites  the  essential  character  of  a  turbinated  Trochus 
with  those  of  the  patelliform  Calyptrtra,  Capulis,  &c. 
By  following  this  clue,  we  arrive  at  once  among  the 
limpets,  while  the  NaticidcB  branch  off  and  unite  again 
with  the  TurhidcB.  It  is  quite  indifferent  to  our 
present  purpose_,  whether  Haliotis  is  retained  in  the 
Scutibranchia,  or  within  the  confines  of  the  Phytophoga  ; 
but  we  may  here  anticipate  our  subsequent  analysis, 
by  stating  that  it  truly  belongs  to  the  latter,  where  it 
forms  a  particular  family,  representing  the  limpets. 
Having  arrived,  therefore,  among  these  latter  shells,  the 
most  simple  of  all  the  univalve  Testacea,  nature  returns 
to  the  carnivorous  gastropods  through  the  Cyclohranchia 
and  the  Tectibranchia  ;  so  that  the  junction  of  the  latter 
with  the  CyprcBidce,  as  before  remarked,  completes  as 
perfect  a  circle  as  any,  perhaps,  in  the  entire  animal 
kingdom.  From  this  disposition  of  the  groups  results 
the  following  table  of  analogies  :  — 

Analogies  of  the  Ti'ibes  of  Gasteropoda  to  the  Orders 

of  the  Testacea. 

Tribes  of  t     ,     ■     ,  nu         u  Orders  of  the 

/^„  /,,.  «„^«  Analogical  Characters.  T^.y,,  .^, 

Gasteropoda.  °  lestacea. 

r Pre-eminently   typical;     mantle^ 
ZoopHAGA.  ■<      formed  into  one  or  two  long  tu-  >  Gasteropoda, 

C     bular  siphons.  j 

Phytophaga.  Siphons  entirely  wanting.  Dithyra.* 

'Animal  oval,  greatly  depressed;' 
o  1     thebranchia,  in  the  typical  di- 1  x- 

SCUTIBRANCHIA.        <       „;„:„„.  f.. :„„,')      „.,,,    .■:iL.„,,    >- N  UniBRANCHIA. 


Lnimal  oval,  greatly  depressed  ;  '\ 
thebranchia,  in  the  typical  di- f^ 
visions  fringed,  and  placed  on  i 
the  back.  J 


^  ("Tentacula     none;     body   broad,  7  r>. 

Cyclobranchia.     J     oval,  onisciform.  '  j  Parenchymata. 

Sliell,  when   present,   protecting') 
only  a  part  of    the  body,  con- f  . 
cealed  ;  mantle  dilated  into  fin- 1' 
like  lobes.  J 


Tectibranchia.     ■{     ^^J^^  ;  mantle  dilate.l  into  fin'  ^  Cephalopoda 


It  is  not  a  little  extraordinary  that  these  two  series  of 
animals,  which  in  their  external  aspect  are  so  very  dis- 
similar, should  yet  present  such  strong  analogies  to  each 
other  ;  the  Scutibranchia,  in  fact,  may  be  called  A''i(di- 
branchia   provided  with  shells  _;   and,  in  the  same  way, 

*  The  sub-typical  group,  of  course,  is  the  one  here  compared,  and  there 
the  animals  have  no  siphon. 


CHAP.   III.  THE    CARNIVOROUS    TRIBE.  ,      6l 

the  PlanaridcE  among  the  Parenchymata  are  naked 
chitons  (^Cijclohranchia).  The  Cephalopoda,  in  hke 
manner,  are  as  perfectly  represented  by  the  swimming 
tribe  of  the  Tectihranchia ;  and  like  them,  also,  have 
their  shell  internal.  Adverting,  again,  to  the  two  first 
analogies,  we  find  the  primary  types,  the  Zoophaga  and 
the  Dithyra,  furnished  with  long  siphons^  or  tubes, 
which  are  totally  wanting  in  the  secondary  types.  To 
this  table^  however,  w^e  may  hereafter  return  ;  and,  in 
the  mean  time^  w^e  shall  enter  at  once  on  the  most 
typical  families  of  the  entire  class. 

\5S.^  The  tribe  of  the  Zoophaga,  or  rapacious  shell- 
fish, is  distinguished  by   a   tubular    or   proboscis-like 
mouth,  a  respiratory  siphon,  and  two  tentacula,  upon  the 
sides  or  near  the  base  of  which  are  the  eyes.     In  some 
few,    as   in  the   cowries  (^Cypr(Ea\  the  mantle  is  ex- 
ternal, and  almost  envelopes  the  shell ;   and  this,  we  sus- 
pect, is  likewise  the  case  in  some  of  the  Volutidcs,  or 
volutes ;  but  in  general  it  is  internal,  and  of  ordinary 
dimensions.     Nearly  all  are  provided  with  a  horny  oper- 
culum for  closing  the  aperture  of  their  shell ;   but  in  the 
Cones   and   ColumheUirKe   this    is   reduced    to    a    mere 
vestige ;  while  in  the  Cypraidce,  and  such  as  have  the 
lobes  of  the  mantle  very  much  developed,  it  is  unneces- 
sary, and  therefore  does  not  exist.     All  these  variations, 
however,  in  the  operculum  are  slight  and  trivial,  in  com- 
parison  to   those  exhibited   in  the  form  of  the  animal 
and   the  construction   of  the   shell.      Here  the  greatest 
variety,  and  the  most  regular  constancy  in  the  variation 
of  natural  groups,  is  everywhere  discernible.      Hence  it 
is,  that  while  our  primary  attention  must  be  directed  to 
the  variation  of  the  animal,  we  must  still  have  a  suf- 
ficient regard  to  its  testaceous  covering.    It  is  the  abuse, 
and  not  the  judicious  use,  of  a  regard  to  the  shell,  which 
is  to  be  condemned.      A  system  built  only  on  the  vari- 
ation of  the  animal,  would  be  as  useless  and  insufficient 
for  all  practical  or  philosophic    purposes,   as   another 
would  be   detrimental  to  sound  principles  of  classifi- 
cation, if  it  w^as   framed   entirely  on   the  form   of  the 


62  SHELLS    AND    SHELL-FISH.  PART  I. 

shell.  The  first  would  include^  like  the  old  systems, 
all  manner  of  spiral  shells,,  under  the  generic  name  of 
Buccinum  ;  while  the  other  would  p^ace  Parmophorus, 
Fissurella,  and  Umbrella  in  the  same  group  as  the 
limpet,  merely  because  they  had  similar  shaped  shells. 
"While,  therefore,  we  make  this  and  all  our  other  chief 
divisions  to  repose  on  a  primary  consideration  of  the 
soft  parts  of  the  body,  we  regard  the  construction  of  the 
shell  as  much  a  part  and  parcel  of  the  animal  itself,  as 
are  the  wings  of  an  insect  or  the  hard  covering  of  the 
chelonian  reptiles.  The  shell  of  testaceous  animals,  in 
fact,  is  precisely  analogous  to  the  covering  of  the 
tortoises,  and  are  to  be  considered  in  the  same  light, 
• —  that  is,  furnishing  a  secondary,  although  a  very  im- 
portant, set  of  characters  for  the  determination  of  the 
minor  groups.  It  is  not  a  little  remarkable  that,  as  the 
tribe  before  us  is  the  most  completely  organised,  and 
therefore  the  most  typical  of  the  whole  of  the  Testacea, 
so  do  we  find  their  testaceous  coverings  are  the  most 
complicated,  and  by  far  the  most  beautiful  of  all  the 
spiral  univalves.  The  gradual  transitions  of  form  which 
they  present,  even  when  there  is  little  or  no  variation  in 
the  animal,  or,  at  least,  none  that  has  yet  been  detected, 
is  a  clear  proof,  if  any  other  was  wanting,  that  all  our 
secondary  characters  taken  from  the  shell,  are  those 
which  nature  herself  has  employed  to  designate  the  sub- 
ordinate groups.  The  definitions,  therefore,  of  the 
families  in  which  we  shall  now  arrange  this  tribe,  will 
be  mainly  taken  from  the  shell,  at  the  same  time  intro- 
ducing all  such  information  regarding  the  soft  parts  of 
the  inhabitant  as  appear  of  primary  consequence. 

(54.)  The  five  leading  divisions  of  the  Zoophaga  may 
be  thus  named  and  defined:  —  1.  The  MuRiciDiE,  or 
murexes,  having  the  respiratory  siphon  in  general  very 
much  developed,  and  its  corresponding  canal  at  the  base 
of  the  shell  always  straight.  2.  The  Turbinellid^, 
or  turnip -shells,  where  the  base  of  the  shell  is  straight 
and  lengthened,  and  the  pillar  strongly  plaited.  In  both 
these,  the  mantle  of  the  animal  is  never  dilated,  but  is 


CHAP.   III.  FAMILIES    OF    THE    ZOOPHAGA.  63 

of  ordinary  dimensions,  and  drawn  back  into  the  shell 
with  the  animal.  3.  The  Volutid.^,  or  volutes,  having 
the  mantle  much  developed  in  the  typical  species :  the 
column  of  the  shell  is  always  marked  by  regular  and 
well-defined  plaits,  nearly  the  same  as  in  the  last;  but 
the  base  of  the  aperture  is  obtuse,  truncate,  and  notched. 
4.  The  Cypr^id^,  or  cowries,  whose  shells  are  without 
any  spire ;  the  last  whorl  enveloping  all  the  others,  as  in 
the  bullas.  5.  The  Strombid^e,  or  wing-shells ;  the 
only  division  where  the  outer  side  or  lip  of  the  aperture 
is  considerably  dilated.  The  two  first  of  these  are  the 
typical  and  sub-typical  groups  ;  the  three  latter  form- 
ing the  aberrant  circle.     The  whole  are  marine. 

{55.)  The  MuRiciDiE,  or  whelks,  are  resolvable  again 
into  the  following  sub-families,  each  of  which  contains 
genera  and  sub-genera :  ] .  The  Muricince,  or  murexes  *  ; 
2.  The  Cassinw,  or  helmets ;  3.  The  Buccinincp,  or 
whelks  ;  4.  The  PurpurincE,  or  purpuras  ;  and,  5.  The 
NassincB.  These  we  shall  now  enter  upon  in  the  above 
order  of  arrangement. 

(56.)  The  MuRiciN^  is  a  very  diversified  and  (from* 
the  little  yet  knowni  of  the  animals)  a  very  difficult 
group  to  arrange.  Generally  speaking,  they  are  strong 
shells,  of  a  rough  exterior,  without  any  plaits  or  teeth 
either  upon  the  pillar  or  outer  lip  :  the  different  periods 
of  their  growth,  or  rather  of  their  enlargement  by  the 
anim.al,  are  marked  by  thickened  transverse  ribs  called 
varices,  which  are  differently  disposed  in  the  genera :  the 
canal  is  generally  short,  or  of  moderate  length,  but  always 
present,  and  usually  a  little  bent  on  one  side.  The  aper- 
ture is  oval;  and  the  spire  nearly  as  long  as  the  body- whorl. 
They  chiefly  abound  in  the  shallow  waters  of  temperate 
seas;  and  are  either  covered  with  an  epidermis  of  their 
owai,  or  by  extraneous  marine  substances.  The  typical 
genus  is  MureJc,  where  we  find  some  of  the  most  beau- 
tifully coloured  shells,  and  certainly  the  most  elaborate 
in  structure,  among  the  whole  of  the  spiral  univalves. 

*  Sometimes  called  rock-shells,  from  the  roughness  and  irregularity  of 
their  surface. 


64 


SHELLS    AND    SHELL-FISH. 


PART  I. 


This  and  Ranella  appear  to  be  the  two  typical  genera  ; 
but  of  the  three  aberrant  divisions^  Triton  is  the  only 
one  that  has  been  yet  named  or  defined.  The  foliated 
varices  of  Ranella,  and  the  sharp  tubercles  on  the  whole 
shell,  joined  to  the  additional  canal  at  the  upper  part  of 
the  aperture,  indicate  that  this  group  is  naturally  con- 
nected to  Miirex ;  but  the  species  are  very  few,  and 
,  present  no  very  marked  deviation  from  the  typical  form. 
In  Triton,  however,  the  case  is  far  otherwise.  The 
species  are  not  only  more  numerous,  but  exhibit  in  their 
structure  so  many  different  modifications,  that  there  is  no 
one  generic  character  to  which  there  are  not  exceptions 
in  some  of  the  species.  The  most  usual  is  that  of  having 
but  few  varices,  and  these  placed  alternately  ;  whereas 
in  Ranella  they  are  so  united  as  to  form  a  continuous 
ridge  on  each  side  the  shell,  when  it  is  placed  with  the 
aperture  downwards.  But  this  character  is  by  no  means 
constant.    The  animal  {fig.  1.)  is  here  represented  from 


an  unpublished  drawing  by  Guilding  ;  the  tentacula 
are  short,  and  the  eyes  at  their  base.  This  remarkable 
diversity  in  the  genus  Triton  is  easily  accounted  for,  on 
the  ground  that  this  group  contains  representations  of 
all  others  in  the  family,  besides  aberrant  forms  leading 
to  the  more  proximate  genera.  The  two  other  aber- 
rant types,  which  we  consider  as  completing  the  circle 
of  the  Muricince,  we  name  Vitulina  and  Muricidea. 
The  first  is  advancing  towards  Murex,  and  is  repre- 
sented by  the  Mureoc  Vitulinus  of  authors,  and  is  dis- 
tinguished by  having  the  varices  nearly  obsolete,  and 
the  piJlar  smooth,  broad,  and  flattened,  like  a  purpura. 


CHAP.   III.  THE    GASSING,    OR    HELMETS.  65 

The  type  of  Muricidea,  is  the  harp-like  Mureoc  Magel- 
lanicus*  Where,  as  in  very  many  other  of  the  small 
murexes,  the  progressive  growth  of  the  shell  is  marked 
by  longitudinal  ridges,  either  foliated  or  spined,  some- 
times as  close  together,  and  nearly  as  regular,  as  those 
upon  the  harp-shells.  The  outer  lip  is  quite  smooth, 
and  the  inner  Hp  thin  :  there  is  no  internal  groove ;  and 
the  basal  canal  is  almost  always  closed  over,  so  as  to 
form  an  internal  tube,  open  only  at  the  two  ends.  The 
connection  of  this  group  of  Murices  to  the  true  genus 
Murex  is  so  close,  that  they  have  never,  until  now,  been 
separated ;  so  that,  being  connected  to  Triton  by  means 
of  Vitulina,  also  a  Lamarckian  murex,  we  find  the  whole 
forming  a  circular  group  of  themselves. 

(57.)  Ill  the  Cassin.e,  or  helmet-shells,  the  first  cha- 
racter which  strikes  us  is  their  large  and  often  gigantic 
size  :  the  spire  is  remarkably  short;  and  the  base,  instead 
of  being  prolonged,  as  in  the  Muricince,  is  either  truncated 
so  as  merely  to  present  a  wide  notch,  or  is  very  short, 
and  turned  back  on  the  body-whorl.  These  are  the 
typical  characters  of  the  sub- family,  but  much  remains 
to  designate  the  genera.  Our  attention  has  been  more 
especially  called  to  this  group,  not  merely  from^  the  size 
and  beauty  of  the  shells,  but  from  the  great  reluctance 
some  conchologists  have  manifested  to  adopt  the  genus 
CyprcEcassis,  proposed  by  j\Ir.  Stuchbury,  whose  valuable 
Essay  upon  the  growth  of  corals  has  rendered  his 
name  familiar  to  naturalists.  That  Cyprcecassis  pos- 
sessed a  decided  relation,  either  by  affinity  or  analogy, 
to  Cyprcea,  we  had  long  been  persuaded.  But  vre 
freely  confess,  that  previous  to,  and  even  for  some  time 
after,  its  being  proposed  as  a  genus,  we  looked  upon  it 
only  as  a  subordinate  type  of  Cassis.  Anxious,  never- 
theless, to  arrive  at  some  definite  conclusion  on  this 
point,  we  were  induced  to  re-examine  the  whole  of  the 
Lamarckian  genus  Cassis;  the  result  of  which  has  con- 
vinced us  that  our  first  impression  was  erroneous,  and 
that  Cyprcecassis  is  as  truly  a  natural  genus  as  any  in 

*  Ency.  Method,  pi.  414.  fig.  4.  a,  b. 
F 


66 


SHELLS    AND    SIIELL-FISH. 


PART  I. 


the  whole  circle  of  the  Testacea.  It  will  be  needless  in 
this  place  to  enter  into  the  definitions  of  this  and  the 
other  four  genera^  since  they  will  be  found  in  our  sys- 
tematic arrangement ;  but  they  may  shortly  be  cha- 
racterised in  the  folio-wing  manner  :  —  In  Cassidea  and 
Dolium,  the  aperture  of  the  shell  is  always  wdde,  rarely 
with  distinct  varices^  and  the  outer  lip  never  dilated  into 
a  marginal  rim  over  the  body- whorl;  but  in  the  first,  the 
inner  lip  is  reflected,  thickly  marginated,  and  generally 
toothed,  while  in  the  last  it  is  always  thin  :  these  will 
be  found,  upon  analysis,  to  be  the  two  typical  genera. 
In  the  harps  {Harpa),  which  obviously  follow  the  tuns 
(^Doliimi),  the  whole  shell  is  marked  by  varices,  which 
assume  the  form  of  ribs.  Now,  the  ample  information 
given  by  M.  Quoy  on  the  animal  of  this  genus,  not 
only  fixes  its  station  in  the  present  circle,  but  demon- 
strates it  to  be  a  representation  of  the  volutes,  with 
•which  that  admirable  malacologist  compares  it.  This  im- 
portant point  being  determined  upon  such  high  authority 
and  unpremeditated  testimony,  we  arrive,  by  induction, 
at  the  station  of  the  two  remaining  types.  Cyprce- 
cassis,  consequently,  intervenes  between  Harpa  and 
Cassis;  and  this  latter  fills  up  the  interval  between  Cy- 
prcEcassis  and  Cassidea.  Thus,  the  Cassince,  like  the 
MuricincB,  form  a  circle  of  affinity  among  themselves, 
and  present  one  of  the  most  beautiful  set  of  analogies 
to  be  found  among  the  families  of  Testacea. 

Analogies  oftheCASSiyiM  to  theFamiUes q/* Gasteropoda. 


Genera  of  the 

CASSINiB. 

Cassidea. 

DOLIliM. 

Harpa. 


CyPRj1?CASSIS. 


CTypical  ; 
X     straight. 


Analogies. 

basal    cliannel    never ' 


{ 


Cassis. 


Sub-typical. 

Font   of  the  animal  enormously 

large  ;    mantle  dilated  ;   tcnta- 

cula  short. 

r  Aperture  of  the  shell  linear  ;  both") 
lips   regularly  toothed,  the  in-  | 
ner  spreading,  but  never  pro-  )■ 
minent ;  aperture  with  a  ciian-  | 
L    nel  at  each  extremity.  J 

Outer    lip  gibbous  or  angulated  ^ 
above,  considerably  dilated  on  f 
ts  margin  ;  eyes  of  the  animal  T 
ghly  developed.  j 


rOutc 
3  ab( 
1  its 
C     hit 


Families  of 
Gasteropoda. 

muricidj!. 

TuUBINELLIDiE. 
VOLUTIDJE. 


CVPR.EID.C 


STROMBID.E. 


CHAP.   III.  ANALOGIES    OF    THE    MVRICIN^,  Gj 

As  no  very  tangible  analogies  exist  between  the  shells 
of  the  two  first  groups  in  each  column^  we  may  fairly 
presume  that  they  exist  only  in  these  hitherto  not  well 
defined  animals^  particularly  as  it  is  only  by  this  means 
that  the  resemblance  of  Harpa  to  the  ]\Ielons^  or  typical 
volutes^  has  been  established ;  and  yet,  when  we  look  at 
a  harp-shelly  we  cannot  assimilate  it  to  any  other  than  a 
coronated  volute.  The  analogy  between  Cypr(Ecassis 
and  the  cowries  is  too  strong  to  be  insisted  upon  ;  and 
in  this  view  it  is  quite  unimportant  whether  the  former 
has  or  has  not  an  operculum^  for  the  relation,  in  either 
case,  is  clearly  one  of  analogy,  and  not  of  affinity  : 
we  are  disposed  to  consider  the  common  C.  testiculus  as 
the  type,  simply  because  it  puts  on  more  the  aspect  of 
a  cowry  than  any  other  species  we  have  seen ;  it  is  less 
nodulous,  and  its  slender  longitudinal  ribs  accord  more 
with  those  of  Oniscia  and  other  cyprseform  types. 
Cassis,  itself,  is  indubitably  a  prototype  not  only  of  the 
Sti'omhidcE,  but  of  the  NassincE,  to  which  it  at  once 
leads  through  the  intervention  of  Cassidaria. 

(58.)  It  is  not  a  little  remarkable  that  while  the 
genera  of  the  Cassince  represent  the  families  of  the  car- 
nivorous gastropods,  those  of  the  pre-eminently  typical 
Muricince  have  a  more  especial  reference  to  the  sub- 
families, as  will  be  seen  by  the  following  exposition  :  — 

Analogies  of  the  Muricin^  to  the  Sub-families. 

Genera  of  j^^;„„-^<.  Sub-families  of 

MuRiciN^.  Analogies.  Muricid^. 

Murex.  Typicalofthtir  respective  groups.  Cassincz. 

Ranella.  Sub-typical.  Muricin<s. 

r Spire  generally  longer  than  the"! 
Triton.  \     aperture ;    base    short,    nearly  >         Buccinince. 

C     truncate,  straight.  j 

r-.,  ,.  „    ■  f  Inner  lip  broad,  smooth,  and  flat- 7  „ 

Jduhna.  ^     tened ;  basal  channel  narrow,    j         Purpurm<e. 

Muricidea.  Base  of  the  shell  slightly  produced.  'Nassimc. 

Here,  again,  insufficient  acquaintance  with  the  animals 
very  much  lessens  the  interest  of  these  comparisons  : 
and  yet  there  can  be  no  doubt  that  Murex  vitiilinus  of 

F    2 


6s  SHELLS    AND    SHELL-FISH.  PART  I. 

authors  is  more  a  miirex  than  a  purpura,  —  that  Triton 
passes  into  Bnccinuni,  and  therefore  represents  it,  — and 
that,  of  all  the  carnivorous  gastropods  out  of  the  CassincF, 
Murex  JMagellanicus  and  its  alUes  have  the  greatest 
similarity  to  the  harp-shells.  This  is  all  we  would 
maintain.  For  the  rest,  there  is  such  an  extreme  regu- 
larity in  all  the  existing  species  of  Harpa,  that  we  may 
fairly  conclude  the  aberrant  examples  have  become 
extinct,  or  have  possibly  not  been  discovered.  One 
species,  however,  of  Muricidea,  with  the  ridges  of 
31.  Magellanka,  but  with  a  truncated  base,  would  con- 
nect the  two  groups ;  and  when  we  consider  that,  in 
Triton,  the  comparative  length  of  the  channel  is  only 
used  to  designate  the  species,  we  may  fairly  conclude 
there  is  no  violation  of  nature  in  supposing  that  Harpa 
and  3Iuric'idea  pass  into  each  other.  As  for  the  analogy 
between  the  latter  and  yassa,  we  have  at  this  moment 
a  species  of  Muricidea  before  us,  whose  canal  is 
reflected  backwards  precisely  as  in  the  common  ^'i.  ar- 
cularia. 

(59.)  The  typical  distinction  of  the  Nassje  lies  in 
a  very  thick  deposition  of  enamel  which  encircles  the 
aperture,  and  not  only  spreads  far  beyond  the  inner  lip, 
but  forms  a  vitreous  mass  all  over  the  under  part  of 
the  body-whorl.  The  only  other  genus  of  predaceous 
Testacea  having  a  shell  thus  constructed,  is  Cassis,  and 
a  few  tritons,  w^hich  are  probably  its  representatives. 
Nevertheless,  there  are  many  Kassce  which  have  this 
peculiarity  but  slightly  developed,  and  others  in  which 
it  is  not  at  all  apparent ;  in  all,  however,  there  is  a  pro- 
minent internal  ridge  at  the  base  of  the  pillar,  and  a 
small  transverse  tooth  on  the  upper  part  of  the  inner 
lip.  These  shells  are  all  of  a  small  size,  and  abound 
in  the  shallow  waters  of  Southern  Europe  and  the  East. 
Among  the  unpublished  researches  of  Guilding*,  is  a 
highly  finished  drawing  of  a  species  from  St.  Vincent's 
{fiy.2.),  which  throws  an  important  light  on  the  animal : 

*  Now  in  the  possession  of  his  widow. 


CHAP.   III. 


Tin:    NASSIXiE. 


69 


from  this,  it  does  not  appear  to  have  a  probosciform 
mouth ;  but  the  anterior  part  of  the  foot  is  prolonged  into 
a  subulate  point  on  each  side,  and  the  hinder  jmrt  termi- 
nates in  two  little 
tail-like  appendages. 
Now  this  has  much 
of  the  character  of 
our  genus  Leiodo- 
nius  *,  figured  by 
Quoy  and  Gaimard ; 
and,  although  both 
they  and  their  shells  are  too  dissimilar  to  be  placed 
in  the  same  group,  they  may  be  considered  analogous. 

(60.)  The  broad,  spreading,  and  dilated  inner  lip  of 
Cassis  prepares  us  at  once  for  the  sub-family  of  Nassin^e, 
which  is  entered  by  the  genus  Cassidaria  of  Lamarck. 
These  shells  differ  from  all  those  we  have  just  left,  by 
having  the  basal  canal  considerably  more  lengthened, 
and  only  slightly  turned  backv/ards,  without  reposing  on 
the  shell  itself :  they  are  of  an  intermediate  size  be- 
tween the  largest  Nassce  and  the  smaller  helmets  ;  and 
thus  the  gradation  even  of  size  is  preserved.  The  typi- 
cal genus  Nassa  then  succeeds  :  the  species,  although 
all  of  them  small,  are  much  varied  in  shape,  and  in  the 
degree  in  which  the  inner  lip  is  developed;  but  the 
twisted  ridge  at  the  base  of  the  pillar,  the  striated  aper- 
ture, and  the  tuberculated  tooth  at  the  top  of  the  aper- 
ture, are  so  constant,  that  they  must  remain  as  they  now 
are  in  our  systems,  until  their  sub-genera  are  worked 
out.  There  is  one  form,  however,  so  very  remarkable, 
that  we  have  placed  it  as  the  genus  Cyclonassa  *:  it  is 
the  only  snail-shaped  flattened  shell  in  this  tribe ;  and 
the  animal,  when  known,  will  no  doubt  be  very  curious. 
Our  next  genus,  Vexilla,  opens  the  passage  to  the 
Pm'purbife,  which  it  perfectly  resembles  in  general 
form,  and  in  its  broad  depressed  inner  lip ;  but  the  outer 


*  Bucc.  agath^  Quoy,  Voy.  Astrol.  pi.  31.  fig.  17. 

+  Cyclops  of  Montford  ;  but  this  is  a  long  established  genus  of  crabs. 

F    3 


70 


SHELLS    AND    SHELL-FISH. 


PART  I. 


one  is  slightly  inflected,  and  distinctly  toothed.  There 
is  still  wanting  another  genus  possessing  some  of  the 
characters  both  of  Vexilla  and  Cassidaria:  this  genus 
is  Oniscia  Sow.,  where  the  inner  lip  is  still  more  in- 
flected and  toothed,  and  the  spire  much  shorter  than  in 
Vejcilla,  but  yet  with  something  of  the  protruding  basal 
channel  and  general  aspect  of  Cassidaria.  As  INIr, 
Sowerby  has  judiciously  alluded  to  this  affinity,  we  need 
not  defend  its  existence.  The  circle  of  the  Nassince 
thus  becomes  closed ;  since  we  have  returned  to  Cas- 
sidaria, or  to  that  genus  with  which  we  began. 

(61.)  We  shall  now  see  how  beautifully  this  na- 
tural series  coincides  with  that  of  the  Cassince,  and 
rightly  estimate  the  additional  value  attached  to  the 
genus  CyprcEcassiSy  without  which  an  important  link 
would  be  altogether  wanting. 

Analogies  of  the  NASsiNiE  and  the  CASsiNiE. 


Genera  of 


Nassa. 

Cyclonassa. 
Vexilla. 

Oniscia. 
Cassidaria. 


Analogical  Characters. 

fTypical ;  inner  lip  much  develop-"] 
I      ed  ;  spire  not  depressed  ;   base  | 
<{      of    the    pillar   internally  cari-  }> 
I      nated  ;  the  basal  canal  reflected  | 
l_    backwards.  j 

Spire  very  short,  more  or  less  de- 
pressed ;  the  basal  canal  trun- 
cated. 

5  Aperture  very  effuse;  outer  lip? 
X_     often  crenated.  3 

r Ovate;  inner  lip  spreading,  but" 
\  not  margined  ;  outer  lip  thick, ( 
"i  inflexed  ;  both  lips  striated  and  ( 
i,     toothed. 

Vciitricose ;  generally  tubercu- 
lated  ;  basal  canal  curvcdback- 
wards. 


{ 


H 


{ 


Genera  of 

CASSI.NiB. 


Cassidea. 

Dolium. 
Harpa. 

Cyprcecassis. 
Cassis. 


To  dilate  upon  this  table,  would  be  almost  implying 
that  our  conchological  readers  were  purblind.  And  yet, 
for  those  who  are  not  scientific,  we  may  advert  to  the 
intimate  resemblance  which  some  species  of  N'assa  bear 
to  the  small  helmet-shells  in  Cassidea  ;  so  that,  but  for 
their  size,  a  superficial  tyro  would  mistake  one  for  the 


CHAP.   III.  THE    PURPURIN^.  71 

Other.  VexUla  represents^  in  outward  form,  and  most 
perfectly  in  colour_,  Harpula  vexillum,  just  as  Harpa 
typifies  the  crowned  volutes.  Oniscia  and  Cyprcecmsis 
are  perfect  counterparts  of  each  other;  while  Cassidaria 
and  Cassis  complete  this  system  of  analogies.  If  any 
doubt  existed  as  to  the  absolute  union  of  Oniscia  and 
Cassidaria  in  regard  to  affinity,  it  is  set  aside  by  a  re- 
markable shell  obligingly  sent  me  by  ^Irs.  Stuchbury, 
where  the  characters  of  both  are  united.  This  is  of 
much  additional  importance,  because  it  shows  that  Cas- 
sidaria does  not  form  one  of  the  five  types  of  the  Cas- 
sirne,  but  merely  leads  to  them  from  the  Nas since. 
These,  therefore,  are  the  grounds  upon  which  we  have 
adopted  ]\Ir.  Stuchbury's  genus  Cyprcecassis.  And  while 
we  return  his  opponents  our  best  thanks  for  stimulating 
our  attention  to  the  subject,  and  thus  detecting  a  mate- 
rial error  of  our  ow^n,  w'e  sincerely  trust  that  he  himself 
will  prosecute  his  researches  with  the  same  ability  and 
w^th  the  same  success ;  to  the  true  advancement  of  our 
favourite  science  of  Malacology.* 

(62.)  The  PuRPURix^E  form  the  next  sub-family 
in  our  arrangement.  They  include  shells  whose  general 
form  closely  resembles  the  BucciniiKe,  or  whelks,  but 
with  this  difference,  —  that  the  pillar,  without  being  ele- 
vated round  the  margin,  is  very  much  thickened,  yet 
always  more  or  less  flattened  and  depressed — not,  as  in 
the  generality  of  shells,  convex.  This,  in  truth,  is  the 
only  character  seen  in  the  shells,  by  which  this  assem- 
blage is  in  any  way  linked  together.  For  the  rest,  the 
spire  is  almost  always  very  short;  the  aperture  large  and 
wide;  the  inner  lip  not  otherwise  developed  than  by  a 
transparent  polish  spread  over  it,  wdiich  is  sometimes 

*  I  cannot  pass  over  this  opportunity  of  publicly  expressing  my  obliga- 
tions to  his  worthy  brother,  Mr.  S.  Stuchbury,  of  Theobald's  Road,  one  of 
the  tirst  commercial  naturalists  in  I.,ondon,  for  the  free  use  he  has  always 
given  me  of  any  interesting  shells  in  his  collection,  without  the  necessity 
of  purchasing  them  ;  a  liberality  not  always  met  with.  With  him,  I  have 
named  a  series  of  types  of  the  greater  part  of  the  new  genera  here  defined, 
and  1  feel  assured  he  will  supply  them  to  collectors  on  the  most  fair  and 
moderate  terms. 

F    4 


72  SHELLS    AND    SIIELL-FISH.  PART  1. 

thickened  in  the  middle,  so  as  to  form  a  slight  elevation; 
and  in  one  genus  (Rici)iula),  both  lips  being  toothed 
renders  the  aperture  very  narrow  :  they  are  all  heavy, 
thick,  and  rough  shells,  often  armed  with  tubercles  and 
spines,  but  never  with  varices  ;  there  is  generally  an  in- 
ternal groove  at  the  top  of  the  aperture.  The  true  type 
of  the  whole  sub-family,  which  is  a  representation  of  the 
Cyclohranchia,  is  Concholepas,  — a  most  singular-formed 
shell,  which  was  long  classed  as  Patella :  next  to  this 
follows  Monoceros,  having  a  basal  spine  at  the  aperture 
much  developed.  Following  these,  we  place  certain 
shells  where  the  basal  notch  is  so  small  as  to  be  nearly 
obsolete.  Of  all  the  different  modifications  in  the  genus 
Purpura,  as  it  now  stands,  we  think  these  point  out  the 
third  sub-genus,  since  they  are  evident  representations 
of  Cerithuni,  Melania,  and  other  half-emarginate groups: 
the  spire  is  very  short,  and  the  pillar  curves  inwards. 
Following  these,  which  we  distinguish  by  the  name  of 
Microtoma,  come  the  ordinary  PurpurcB;  and  these 
blend  imperceptibly  into  Riciyiula,  by  means  of  P.  coin- 
mellaris,  and  Ricinula  aspera  and  morus.* 

(QS.^  Ricinula  is  a  most  remarkable  genus  of  small 
prickly  shells,  with  a  very  short  spire,  and  the  mouth, 
in  the  typical  species,  so  beset  on  both  sides  with  tooth- 
like projections,  that  the  aperture  itself  becomes  remark- 
ably narrow  ;  but  these  teeth  are  only  developed  at  the 
matured  age  of  the  animal,  and  even  in  some  species 
they  are  very  small ;  nevertheless  the  pillar  is  almost 
always  flattened.  The  gradual  developement,  and  some- 
times the  digitated  outer  margin,  of  the  external  lip, 
shows  a  strong  analogy  to  the  Stronibidte,  while  the 
toothed  aperture  instantly  reminds  us  both  of  Cohunhella 
and  Cassis :  all  these  relations  will  be  still  more  deter- 
minate, if  the  circle  of  the  Purpiirince  is  tested  on  the 
same  principles  as  those  last  examined.  It  is  this  group, 
in  fact,  which  unites  the  Purpurince  with  the  NassincSy 
by  means  of  Vexilla,  where  we  see  in  the  toothed  outer 

*  Ency.  Meth.  pi.  317.  tig.  4.  6.  t  Ibid.  pi.  317.  fig.  5. 


CHAP.   III. 


THE    BUCCININ^ffi;. 


73 


lip  the  last  indication  of  Ricinula.  The  connection^ 
again,  of  these  singular  shells  to  Concholepas  seems  to  be 
effected  by  our  Ricinula  planospira\,  which  has  the 
spire  nearly  obsolete.  This,  as  we  believe,  is  the  true 
course  of  the  circle,  the  contents  of  which  find  their  re- 
presentatives in  the  sub-families.  It  really  seems  ad- 
visable that  the  sub-genera  of  Ricinula,  Nassa,  Triton, 
and  such  varied  groups,  should  be  characterised  when 
the  science  is  somewhat  more  advanced. 

(64.)  There  is  one  set  of  analogies,  however,  result- 
ing from  this  disposition  of  the  PurpuriniB,  which  we 
cannot  omit,  because  it  illustrates  that  sub-family  by 
which  they  are  represented  in  the  circle  of  the  Turhi- 
nellidcE,  —  namely,  the  PyruUncE.  This  will  also  save 
much  useless  repetition  when  we  come  to  speak  of  the 
latter  group. 


Analogies  of  the  PuRPURiNiE  and  the  Pyrulin^. 


Genera  of  the 

PURPt'RlN.E. 

Pillar  flattened. 

Concholepas. 

Monoceros. 

Microtoma. 

Purpura. 
Ricinula. 


Analogical  Characters. 

r Shell  smooth;  spire  excessively T 
-5  small,  scarcely  projecting;  aper-  V 
c     ture  very  efifuse.  j 

Spire  more  lengthened,  conic, 
r  Shell  smooth  ;  spire  small ;  aper 
■5     ture  very  effuse ;  the  basal  ca 
C     nal  narrow  and  almost  obsolete. 

Shell  ponderous,  rough,  often 
spired  ;  basal  canal  wide,  and 
fully  developed. 

Pillar,  or  inner  lip,  toothed. 


{ 


^ 


Genera  of  the 

Pyrlltn^.. 
Pillar  convex. 

Ficula. 

Pyrula. 

Rapella. 

Myristica. 
Cuma. 


Considering  that  these  sub-families  belong  to  two  supe- 
rior divisions,  of  which  each  is  the  most  aberrant  type, 
the  coincidence  of  each  agreeing  in  their  details,  is  not 
a  little  remarkable. 

{Q5.')  The  BucciNiN^,  or  whelks,  form  the  fifth  and 
last  division  of  this  family :  they  are  known  from  the 
murexes  by  having  no  varices,  and  from  the  PurpurincB 
by  the  pillar  not  being  flattened :  they  are  generally  re- 
cognised by  the  abrupt  termination  of  the  base,  v^'hich 
is  deeply  notched.     They  are  nearly  all  smooth  shells, 


74f  SHELLS    AND    SHELL-FISH.  PART  I. 

or  at  least  without  spines^  or  very  prominent  nodules. 
The  typical  genus  is  Terebra,  —  the  longest  spired  group 
of  all  the  carnivorous  gastropods^,  but  so  closely  resem- 
bling TurrUella,  that  the  difference  in  their  apertures 
alone  distinguishes  the  shells.     In  the  genus  Bucciiium, 
the  spire  is  much  shorter^    and  the  body-whorl  more 
ventricose.     These  seem  to  be  the  typical  groups.    The 
three  aberrant  will  be  now  described.     The  first,  which 
appears  to  us  to  make  the  nearest  approximation  to  the 
wide-mouthed  genus  Microtoma,  is  Leiodomus,  founded 
upon  two  shells,  the  animals  of  which  have  been  beauti- 
fully figured*  by  M.  Quoy.     One  of  these  is  the  Bucci- 
num  Icevigatum  of  authors;  the  other,  XheB.Achatinum.f 
Both  these  have  the  foot  of  an  immense  size,  so  that  it 
spreads  over  a  circumference  near  three  times  as  large 
as  the  shell,  and  is  sufficient  to  envelope  it  entirely.    In 
other  respects  there  are  some  slight  points  of  variation 
between  the  two;  but  they  do  not  strike  us,  at  present, 
of  sufficient  moment  to  sanction  the  formation  of  sepa- 
rate genera.     To  these  we  add  the  Terebra  vittata  j, 
and  three  or  four  other  species,  apparently  undescribed. 
The  vittata,  however,  appears  aberrant,  and  leads  im- 
mediately to   Terehra.     We  are  disposed  to  consider, 
also,  as  the  type  of  another  genus  (  Trochia),  the  species 
of  Purpura  of  that  name, — since  its  characters  will 
not  agree  with  those  of  Purpura,  while   the   striated 
inner  lip  leads  to  the  conjecture  that  it  is  a  prototype  or 
Oniscia  and  similar  shells.     Lastly,  we  have,  in  Tri- 
tonidea  §,  a  remarkably  varied   group    of  small  shells, 
some  of  which  resemble  Triton,  and  others  Buccinum; 
the  base,  however,  is  always  contracted,  and  even  slightly 
produced ;   the  pillar  marked  at  the  base  with  elevated 
granulations,  or  short  obsolete  plaits ;  and  a  distinct  canal 
at  the  top  of  the  aperture.   The  connection  of  this  group 
to  Buccinum  is  very  obvious,  while  its  union  to  Triton 

*  Encv.  Mcth.  j)l.  400.  fig.  1. 

f  Ibid.  pi.  400.  tig.  4.  J  Ibid.  pi.  402.  fi?.  4. 

^  I  have  since  learned  that  this  genus  is  the  same  as  Po/li'n  Gray.  —  a 
name  1  should  gladly  liave  adopted,  had  it  not  previously  been  given  to  a 
genus  of  European  Lcpidoptcra. 


CHAP.    III.  THE    TURBlNELLIDiE.  75 

is  even  more  so.  Triton  ckmdestinum  has  the  obsolete 
plaits  and  the  mternal  channel  of  Tritonidea  ;  while  its 
thickened  outer  lip  and  more  produced  channel  is  suffi- 
cient to  give  it  a  place  within  the  limits  of  Triton.  The 
circle  of  the  MuricidcB  is  thus  complete ;  but  whether 
Leiodomus  is  a  sub-genus  of  Terebi-a,  or  really  that  type 
which  passes  into  Microtoma,  is  a  matter  of  doubt ;  its 
analogy,  however,  to  Harpa,  as  shown  in  the  animal,  is 
a  weighty  consideration,  although  we  have  no  interme- 
diate links  by  which  it  is  connected  to  Trochia. 

(66.)  The  TuBBiNELLiDiE  form  our  next  great  di- 
vision of  the  predatory  sheU-fish.  As  the  Muricidce 
are  chiefly  distinguished  by  the  general  shortness  of  the 
testaceous  canal  which  receives  the  respiratory  siphon,  or 
by  its  total  absence;  so  may  the  great  majority  of  the 
TurhinellidcB  be  known  by  this  canal  being  considerably 
lengthened.*  The  animals,  unfortunately,  of  nearly  all 
the  typical  genera  are  as  yet  quite  unknown  f;  so  that 
we  have  only  a  few  detached  land-marks,  as  it  were,  to 
assist  us  in  the  arrangement  of  their  shells.  Looking, 
therefore,  to  such  characters,  we  observe  that  the  Tiir- 
hinellida,  as  a  whole,  are  remarkable  for  the  length  of 
the  basal  canal ;  and  that  the  two  typical  sub-families 
have  the  pillar  plaited,  —  a  character  never  met  with  in 
the  Muricidce.  The  volutes,  indeed,  possess  it ;  but  the 
total  absence  of  a  canal  in  those  shells  serves  at  once  to 
distinguish  them.  We  shall  now  arrange  the  whole 
under  the  following  families:  —  1.  TuRBiNELLiNiB, 
having  a  large,  very  heavy,  and  smooth  shell,  the  canal 
nmch  lengthened,  and  the  spire  generally  papillary.  2. 
ScoLYMiNiE,  equally  strong  and  ponderous  with  the  last, 
but  the  shell  is  rough,  with  foliated  spines  or  tubercles, 
as  in  Murex,  and  the  canal  short.  These  two  are  the 
typical  groups ;  the  first  representing  the  Cassintr,  the 
second  the  Muricince  of  the  last  family ;  and  both  are 

*  Except  in  the  Eburnidce,  and  some  of  the  aberrant  ScohjmincE. 

t  Guilding  has  ascertained  that  oi  Scolymus,  and  Quoy  those  oi  Eburna 
and  Strutheolaria  :  the  former  has  not  a  probosci^brm  mouth,  but  the  two 
latter  have  this  structure  highly  developed. 


76  SHELLS    AND    SHELL-FISH.  PART  I. 

furnished  with  distinct  plaits  on  the  pillar.  3.  The 
Eburninje,  where  the  base  of  the  shell  is  truncate  and 
notched^  the  pillar  smooth,  and  the  inner  lip  considerably 
thickened  and  spreading.  4.  The  Pyrulin^e,  or  pear- 
shells,  having  the  spire  short,  the  pillar  smooth  and  con- 
vex, and  the  canal  moderate.  5.  and  lastly.  The  Fusin^e, 
or  spindle-shells,  slender  and  delicate,  having  the  canal, 
as  well  as  the  spire,  remarkably  long,  and  generally  of 
nearly  equal  length.  As  it  will  subsequently  appear 
that  these  groups  are  of  the  same  rank  and  value  as  those 
of  the  CassincB,  we  have  given  them  the  same  termin- 
ation in  ince,  although  their  contents  are  by  no  means  so 
numerous  as  their  prototypes. 

(67.)  The  TuRBiNELLiN^  are  remarkable  in  their 
typical  genus,— which  is  Turhmella, — for  the  excessive 
heaviness  and  even  the  size  of  their  shells,  for  in  this 
latter  respect  they  almost  equal  any  others  of  the  family. 
Their  surface,  although  usually  smooth,  is  generally 
covered  with  an  epidermis  :  the  outer  lip  is  rather  thin 
and  simple,  but  the  inner  is  frequently  thickened  and 
margined  at  its  basal  half :  there  are  three  or  four  very 
strong  transverse  plaits  on  the  pillar,  placed  nearer  to 
the  top  than  to  the  bottom  of  the  aperture  ;  but  the 
uppermost  is  always  largest — not,  as  in  the  Volutidce, 
the  smallest.  Like  these  latter  shells,  also,  the  tip  of 
the  spire  is  almost  always  papillary  ;  but  this  part  is 
small,  and  assumes  a  very  different  appearance  to  that  of 
of  the  true  volutes.  The  next  genus  we  shall  notice — 
(there  being  an  hiatus  in  this  part  of  the  series,  which 
we  shall  subsequently  advert  to) — is  Fasciolaria,  where 
the  spire  is  so  much  lengthened,  as  to  be  longer  than 
the  canal, —  thus  reversing  the  proportion  between  these 
parts  as  seen  in  Turbinel/a.  The  plaits  on  the  pillar 
are  small,  placed  close  to  the  bottom  of  the  aperture, 
and  generally  not  more  than  two  ;  the  last  being  by 
far  the  largest.  Some  of  these  large  shells  are  smooth, 
but  a  few  are  corrugated  or  wrinkled;  thus  preparing  us 
for  the  ScolymincB,  to  which  they  directly  lead.  Two 
other  genera,   however,  enter   into  this  circle:    one   of 


CHAP.   III.  THE    TURBIXELLIN^.  77 

these   we  designated^  on   a   former   occasion*,  as   the 
Pyrella  spinlla  :  it  so  completely  represents  Pyrula  in 
this  group,  that  no  one  can  mistake  the  analogy ;  while 
it  differs  from  the  old  TurhinellcBi  by  having  no  other 
indication  of  teeth  hut  a  sharp  ridge  along  the  bottom 
of  the  aperture.    Following  this,  we  assemble  nearly  all 
the  fossil  TiirhinellcB  under  the  name  of  ClavaUthes: 
they  form,  in  our  estimation,  one  of  the  best  defined 
and  most  natural  groups  in  malacology  ;  and  our  only 
surprise  is,  that  they  never  should  have  been  so  defined 
by  Lamarck.     The  species,  we  believe,  are  all  found  in 
the  plastic  clay  formations.     They  have  hitherto  been 
confounded  with  Fusus,  but  they  clearly  hold  an  in- 
termediate station  between  that  genus,  or  rather  sub- 
family, and  the  typical  TurhineU(F,  close  to  which  we 
now  arrange    them.       The    ClavaUthes,  in    short,    are 
Turhinellce,   without  plaits  on  their  pillar,  and  with  a 
more  lengthened  spire,  but  the  tip  of  which  is  also  pa- 
pillary :   the  smoothness  of  the  inner  lip,  and  the  fusi- 
form shape  of  the  shell,  has  probably  induced  authors 
to  place  them  with  Fusus ;  but  the  great  size  of  the 
body-whorl,  the  papillary  spire,  and  the  thickness  and 
general   habit  of   all   these    shells,   bring    them    much 
nearer  to  Turh'melki.     Several  species  occur  among  the 
fossils  of  the  Paris  basin;    and  one  or  two  of  gigantic 
size  are  found  at  Hordwell  Cliff,  in  Hampshire.     We 
have  now  indicated   four  of  the  types  of  form  or  ge- 
nera, Avhich  compose  the  natural  series  of  the  Turbi- 
NELLiN^  :    but  there  is  a   hiatus  between   Turhinella 
and  FascioJaria  ;   and  this  cannot  be  filled  up  by  any 
shells  which,  so  far  as  we  are   aware,  have   yet  been 
published.       As  this    form,   according   to    our    theory, 
should    represent    Scoli/mus    and    Murex,    we    should 
expect  it  would  have  the  general  shape,  and  plaits  on 
the  pillars,  of   Turhinella,  but  with   the  rugosity   and 
perhaps  the  spines  of  a  Scolymus  or  Murex,    Now,  such 
a   recent  shell  we  have  a  distinct  recollection  of  see- 
ing, many  years  ago,  in  the  hands  of  a  dealer ;  and  we 

*  Zool.  111.  series  i. 


78  SHELLS    AND    SHELL- FISH.  PART  I. 

remember,  at  the  time^  being  completely  puzzled  as  to 
what  genus  it  should  be  placed  in.  This,  of  course, 
was  when  we  were  entirely  ignorant  of  those  prin- 
ciples of  variation  in  the  MoUusca  here  developed ; 
but  we  made  a  memorandum  of  the  occurrence  at  the 
time,  conjecturing  that  it  might  hereafter  be  useful. 
Such  we  now  think  it,  inasmuch  as  it  realises  the  very 
form  which  is  requisite  to  complete  the  circle  we  are 
now  upon.  Finally,  the  long  spire  of  Clavalithes  is 
continued  to  TurbineUa  Scolymus*,  which  differs  only 
in  this  respect  from  T.  rapa.f 

(68.)  The  ScolymincB,  as  already  remarked,  are 
rough,  blunt-spined  shells,  having  the  aspect  of  many 
of  the  Linnsean  murexes  :  but  the  canal,  although  short, 
is  straight;  the  pillar  is  furnished  with  distinct  plaits, 
generally  central ;  while  the  spire  is  always  pointed. 
The  animal  we  can  fortunately  describe  from  the  un- 
published drawings  of  our  late  friend  Guilding :  the 
foot  of  Scolymus  is  a  little  longer  than  the  aperture,  the 
the  breadth  measuring  one  half  the  length  ;  the  oper- 
culum semicircular,  and  tolerably  large,  as  in  Fascio- 
laria;  the  peduncles  of  the  eyes  very  long,  the  eyes 
themselves  being  placed  more  than  half  way  from  the 
base  to  the  tip  ;  the  anterior  part  of  the  foot  is  truncate, 
with  the  angles  rounded ;  the  hinder  part  is  also  rounded  ; 
the  mouth  is  not  probosciform  ;  and  the  respiratory 
siphon  is  rather  short.  We  cannot  make  use  of  this 
information  to  the  extent  that  could  be  wished ;  but  it 
will  become  doubly  valuable  for  comparison,  so  soon  as 
the  animals  of  TurbineUa  and  of  the  neighbouring 
genera  are  made  known.  The  first  form  which  pre- 
sents itself  in  this  division,  after  leaving  Fasciolaria,  is 
our  genus  FlicatcUa, — an  extensive  group  of  small  shells 
hitherto  confounded  with  Fasciolaria  and  Sco/i/nins. 
From  the  first,  they  are  known  by  the  little  plaits  upon 
the  pillar  being  almost  transverse  (as  in  Scoli/miis),  and 
not  oblique,  as  in  Fasciolaria;   these  plaits  are  likewise 

*  Ency.  Mcth.  pi.  431.  bis,  fig.  2.  +  Ibul.  fig.  1. 


CHAP.   III.  THE    SCOLYMIN^.  79 

much  less  distinct,  and  of  the  same  thickness,  without 
the  last  being  manifestly  larger;  they  are  always  situated 
across  that  part  of  the  pillar  which  forms  the  lowest 
part  of  the  aperture,  and  not,  as  in  Scolymus,  higher  up 
towards  the  middle ;   the  situation  of  these  plaits,   in 
short,  removes  the  genus  from  Scolymus,  while   their 
form  and  direction  separate  it  from  Fasciolaria.      The 
variation  in  the  shape  of  the  shells  is  precisely  what 
may  be  expected  from  this  intermediate  position.      In 
such  as  approximate  to  Fasciolaria,  the  canal  is  nearly 
as  long  as  the  spire;  while  in  those  wliich  lead  to  Scoly- 
mus, it  is  shorter  :  many  of  the  species,  again,  put  on 
the  aspect  of  the  spindle-shells  (Fusus),  and  hence  have 
been  arranged  among  them";  while  others  have  the  exte- 
rior aspect  of  Murex.     They  are  all  of  a  m.oderate  or 
small  size;  and  may  be  known  from  the  Muricidtp  by 
the  distinctness  of  their  transverse  plaits,  the  absence  of 
internal  tubercular  teeth  on  the  inner  lip,    and   their 
longer  channel :   they  are  united  to  the  next  genus  by 
Scolymus  (or  Plicatelki)  capitellum, — a  shell  which  may 
be  placed  in  either  group  without  any  violation  of  na- 
ture :   its  predominant  characters,   however,   appear  to 
us  to  be  those  of  the  last,  inasmuch  as  the  three  plates 
are  nearly  of  equal  thickness;  whereas,  in  Scolymus,  the 
lower  are  generally  much  smaller  than  the  upper,  and 
their  situation  is  much  higher.     This  last-named  genus 
is  a  very  striking  one,  and,  being  now  disencumbered  of 
Plicatella,  admits  of  a  much  more  precise  definition  than 
we  originally  gave  it*:   the  shells  are  short,  excessively 
heavy;  the  spire  acute,  and  almost  turbinate:  the  pillar 
short;    the  canal  straight,  and  longer   than   the   spire; 
while   the   whorls  are   rugged,   and    beset  with   blunt, 
simply  folliculated,  or  plaited  spines.     All  the  species 
are  from  warm  countries. 

(69-)  There  is  strong  evidence  to  believe  that  the 
natural  situation  of  Cancellaria  is  immediately  after 
that  of  Scolymus;  for,  although  the  two  genera,  in  their 
typical  chaiacters,  are  very  different,  v^^e  once  possessed 

*  Elements  of  Conchology,  p.  21, 


80  SHELLS    AND    SIIELL-FISH.  PART  I. 

certain  species  which  exhibited  so  many  intermediate 
characters,  that,  but  for  the  pecuHarly  small  and  incurved 
channel  of  Cancellaria,  we  should  have  been  at  a  loss 
where  to  place  them  :  one,  we  more  particularly  remem- 
ber, had  an  exceedingly  wide  umbilicus,  nearly  as 
large  as  the  Scolymus  iimbilicaris* ,  with  a  very  simi- 
lar shaped  shell;  and  it  is  not  a  little  remarkable  that, 
in  the  figure  of  this  very  Scolymus,  the  base  of  the 
pillar,  instead  of  being  straight,  as  in  all  the  other 
species,  is  represented  as  curved  inwards,  and  with  an 
exceedingly  small  notch,  —  two  characters  which  are 
absolutely  peculiar,  in  this  group,  to  Cancellaria. 

(70.)  The   fourth   genus,    Rhinedomus,  is  typically 
represented  by  the  Cancellaria  senticosus  of  Lamarck, 
but  of  which  there  are  several  species.      It  retains  suf- 
ficient of  the  characters  of  CancellaricB  to  show  its  true 
affinity  to  them,  for  the  exterior  surface  is  longitudinally 
ribbed,  and  rough  with  little  points,  and  there  are  two 
distinct  folds,  or  rather  one  deep  groove,  at  the  base  of 
the  pillar :    but  in  all  essential  respects  the  true  cha- 
racters of  Rhinedomus    are   remarkably   different  :  the 
basal  canal  is  fully  developed,  being  deeply  notched ; 
and,  what  is  very  unusual,  there  is  a  distinct,  though 
not  a  very  deep,  sinus  close  to  the  base  of  the  outer 
lip.     The  animal,  made  known  to  us  by  the  valuable 
researches  of  MM.  Quoy  and  Gaimard,  is  most  remark- 
able ;  but,  until  we  are  acquainted  with  that  of  Cancel- 
laria, it  furnishes  no  comparison  with  them.   The  other 
species  of  Rhinedomus  have  the  spire  less  elongated, 
and  thus  open  a  passage   to    our  new  genus  Polytropa, 
examples  of  which  will  be  found  in  two  well-known 
British  shells,  the  Purpura  lapillus  and  imbricatus  of 
Lamarck  :   this  genus  agrees,  indeed,  with  Purpura,  in 
common  with  many  other  of  its  prototypes,  in  having 
the  inner  lip  flattened ;  but  the  base  of  the  shell,  in- 
stead of  being  truncate,  forms  a  short  straight  channel; 
the  spire  is  always  as  long  (generally  much  longer)  as 

*  Ency.  Mt'thod.  pi.  431.  bis,  fig.  1. 


CHAP,   111.  THE    EBURNIX^.  81 

the  aperture ;  there  is  also  no  internal  canal  :  the  inner 
lip  sometimes  has  a  row  of  tubercles.  The  most  typical 
species^  however,  is  the  Polytropa  crispata.*  As  we  re- 
cede from  this  genus,  and  approach  to  Plicatella,  we 
find  the  spire  increasing  in  length  ;  the  numerous 
crisp  undulations  give  place  to  small  nodules  and  Uttle 
tubercles  at  the  base  of  the  inner  lip,  so  that  the  two 
genera  became  united  :  the  circle  of  the  ScolymincB 
is  closed ;  and  this,  without  the  deficiency  of  a  single 
link  in  the  chain  of  connection  which  binds  all  the  five 
genera  together, 

(71.)  The  next  sub-family,  EburnirKP,  is  one  of  very 
great  interest,  since  it  brings  together  certain  genera 
whose  station  has  hitherto  perplexed  us  all.  For- 
tunately, how^ever,  Mr.  Gray  has  characterized  the  re- 
markable little  genus  Cyllene ;  and  the  possession  of 
other  species,  joined  with  those  of  Rhinedomus,  before 
alluded  to,  have  prevented  us  falhng  into  some  errors : 
the  discovery  of  the  basal  sinus,  also,  on  the  outer  lip  of 
Rhinedomus,  at  once  opens  a  passage  to  Cyllene,  which 
still  retains  a  costated  and  somewhat  cancellated  exterior, 
with  the  basal  sinus  of  the  last  genus.  It  deserves  es- 
pecial notice,  that  the  species  described  by  Mr,  Gray 
has  a  distinct  channel  round  the  suture,  but  the  other 
we  possess  has  not.  Now,  this  variation  is  precisely 
what  is  met  with  in  the  genus  Ebiirna,  the  types  of 
which  are  channeled,  the  others  not.  The  slight  striae 
at  the  base  of  the  pillar  in  Cyllene,  are  explained  by 
its  analogy  to  Oliva,  just  as  its  obsolete  notch  typifies 
its  reference  to  Stromhus.  Other  species  will  no  doubt 
soon  come  to  light  ,•  so  that,  with  these  facts  before  us, 
we  have  no  hesitation  in  placing  Ehurna  as  the  next 
type.  Between  this  last,  and  Striithiolano.  there  exists 
the  most  intimate  relationship  in  regard  to  their  animals ; 
both  have  a  comparatively  small  foot,  but  a  probosci- 
diform  mouth  of  excessive  length,  particularly  that  of 
Struthiolaria,  which,   when  fully  protruded  t,  is  more 

*  Chemnetz,  187.  fig.  1802,  1805.    Ency.  Meth.  pi.  419.  fig.  2. 

f  See  the  animal  of  Strutk.  crenata.  Voy.  d'Astrolobe,  pi.  31.  figs.  8,  9. 

6 


82 


SHELLS    AND    SHELL-FISH. 


PART  I. 


than  equal  to  the  entire  length  of  the  shell,  while  the 
operculum  is  only  rudimentary.  A  singular  unde- 
scribed  shelly,  just  communicated  to  us  by  Mr.  Stuch- 
bury,  is  evidently  intermediate  between  the  shape  of 
the  shells  of  Ehiirna  and  Struthiolaria ;  so  that  this 
part  of  our  series  is  definite.  We  must  now  return  to 
Cyllene,  for  the  purpose  of  showing  its  close  approxi- 
mation to  the  fourth  genus^  Pseudoliva,  the  type  of 
which  is  the  Buccinum  plumheum  of  Linnsean  authors. 
The  very  aspect  of  this  {^fig.  3.  a)  is  quite  sufficient  to 
show  its  proximity  to 
Cyllene,  and  its  abso- 
lute connection  with 
the  VolutidfB  by  means 
of  Olivillahiplicata  (&). 
Last  of  all,  as  forming 
a  passage  to  the  Py- 
rulcBy  we  have  Lati- 
axis  MawcB*  (Sw.), 
where  thechannelround 
the  whorls  is  so  broad  that  they  become  almost  discon- 
nected. At  first  sight,  this  shell  would  appear  a  mon- 
strosity, did  w^e  not  remember  its  prototype,  Scalaria 
pretiosa,  not  to  mention  the  tribe  of  Tuhulihranchia. 
We  consider  it  therefore  as  perfect  in  its  kind,  related  to 
aU  the  types  we  have  noticed  by  its  channeled  suture,  to 
Ehurna  by  its  large  umbilicus,  and  to  Rapella  (the  first 
genus  of  the  PyrulhKv)  by  something,  very  difficult  to  de- 
scribe, in  its  general  shape.  The  whole  sub-family  may 
therefore  be  defined  as  shells  whose  base  is  truncate,  having 
a  channel  more  or  less  developed  round  the  whorls,  an 
aperture  contracted  at  its  base,  and  generally  either 
emarginate  as  in  Ehurna,  or  very  slightly  notched  as 
in  Struthiolaria  and  Latiaxis  :  the  inner  lip  is  much 
developed  and  spreading,  without  having  a  defined 
margin.  The  following  table  will  also  exhibit  some  of 
its  analogies  ;  the  group,  as  a  whole,  being  evidently  a 
representation  of  the  NassincB  in  the  neighbouring 
family  of  the  Muricidce. 

*  Griff.  Cuv.  pi.  25.  figs.  3,  4. 


CHAP.   III.  THE    PYRULIN^.  83 


Analogies  of  the  Eburnix^. 

Genera  of  the  4..„;^„;„„7  r'A„..„^/^v„  Families  of  the 

Eburmnj^..  Analogical  Characters.  Zoopkaga. 

Struthiolaria.  Shell  nodulous  or  muricated.  MuRiciDiE. 

Eburm.  I  ^'deUbped.' '  '^^  "'"''  ^'^  """'^  ]  Turbixellid^. 

Cyllene.  P  Uncfsinus.''"*"  ''^  '''^^  ^  ^'''  ]  StROmbid^. 

Pseudoliva.  Oval,  smooth.  Cypr^id^, 

r^/,-^.-»  f  Spire  excessively  short  and  irre-^-tr^, r,^, 

Lahazis.  I    'g^i^^.  jhg  ^^^J^^  sub-coronated,  j  Volutid^. 

This  comparison  explains  the  relation  which  Sti'uthio- 
laria  has  been  thought  to  have,  by  some  writers,  to 
the  murexes  :  the  smoothness  of  all  the  Ehm'nirKx  is 
remarkable,  and  is  no  doubt  an  indication  of  their  re- 
lation to  the  typical  TurhineUidcE.  The  lobe  of  Cyllene, 
again,  is  borrowed,  as  it  were,  from  the  Stromhidte,  in 
order  to  show  the  analogy  of  both.  The  excessive  short 
spire  of  the  two  next  is  explained  on  the  same  ground  ; 
while  the  irregular  spire  of  Latiaxis  is  to  be  found  in 
no  other  shells  of  the  zoophagous  tribe,  than  those  of 
the  typical  volutes  or  melons. 

(72.)  In  the  Fyridince,  or  the  fourth  division  of  the 
family,  we  place  the  greatest  part  of  those  exceedingly 
diversified  shells  forming  the  genus  Pyrula  of  modern 
writers.  They  are  so  designated  from  their  generally 
being  pear-shaped  ;  the  basal  portion  representing  the 
stalk  end  of  that  fruit,  and  the  spire  and  w^horls  the 
other.  This  comparison,  indeed,  is  so  far  apt,  that  it 
gives  a  very  good  idea  of  the  shape  most  prevalent 
among  them,  notwithstanding  the  great  differences  they 
present,  in  other  respects,  among  themselves.  This  is 
one  of  the  few  natural  groups  in  malacology,  of  which 
we  shall  endeavour  to  give  as  complete  an  analysis  as 
a  long  and  protracted  investigation  of  their  relations 
will  permit.  We  have  invariably  found,  that  where 
natural  assemblages  such  as  this,  in  any  division  of 
the  animal  kingdom,  contain  a  great  number  of  subor- 

G   2 


84  SHELLS    AND    SHELL-FISH.  PART  I. 

dinate  variations,  such  groups  are  the  best  calculated 
for  discovering  the  true  principles  of  variation.  The 
interchange  of  characters  between  one  division  and 
another  is  better  marked  —  the  gradations  more  gentle 
—  the  links  more  perfect ;  and  hence,  by  carefully 
tracing  the  transitions  from  one  form  to  another,  we  have 
a  better  chance  of  correcting  our  previous  errors,  and 
of  discovering  the  fallacy  of  any  preconceived  theory, 
than  if  the  hnks  were  so  wide  apart  as  to  leave  the 
imagination  to  till  them  up,  by  supposing  that  they  have 
existed,  or  that  they  are  not  yet  discovered.  The 
complete  analysis  of  any  one  group,  where  these  defi- 
ciencies do  not  occur,  is  far  more  worthy  the  attention 
of  the  scientific,  and  even  the  general,  reader,  than 
numberless  others  whose  links  are  incomplete. 

(73.)  The  most  striking  characteristic  of  the  shells 
composing  this  sub-family,  next  to  their  pear-shaped 
form,  is  that  belonging  to  the  inner  lip  and  the  colu- 
mella, or  pillar.  It  will  be  remembered,  that  in  the  Pu7'- 
puriiKT,  the  inner  lip,  properly  speaking,  is  merely  a 
thin  glazing  spread  over  that  part  of  the  pillar  which 
forms  the  left-hand  side  of  the  aperture :  in  this  respect 
they  differ  not  from  the  shells  now  before  us  ;  but  the 
pillar,  instead  of  being  broad,  flat,  and  even  concave,  as 
in  all  the  Purpurce,  is  invariably  rounded,  and  conse- 
quently very  convex  :  the  shape  of  the  Pyrulce,  also, 
necessarily  renders  the  base  of  the  shell  much  narrower, 
and  the  canal  much  longer,  than  in  their  prototypes ; 
although  the  degree  of  length  of  this  channel,  as  well  as 
that  of  the  spire,  cannot  enter  into  the  general  defini- 
tion, since  it  will  be  seen  that  these  are  subordinate  cha- 
racters. The  five  principal  modifications  of  form  under 
which  we  arrange  all  the  species,  are  these:  —  1.  Pi/rula, 
where  the  shells  are  strong  and  solid  ;  the  whorls  ge- 
nerally muricated ;  the  spire  short,  yet  elevated,  well 
defined,  and  often  slightly  papillary  ;  the  inner  lip  en- 
tirely wanting;  and  the  canal  considerably  lengthened. 
The  Pyrula  perversa  may  be  taken  as  the  type  of  this 
genus,  all  of  which  are  strong,  solid,  and  muricated  spe- 


CHAP.  III.  THE    PYRULIN^.  85 

cies.  2,  Ficula,  where  the  great  elongation  of  the  canal 
is  still  preserved^  but  the  shell  is  differently  formed, 
and  its  substance  very  thin.  The  body-whorl  is  nnore 
or  less  ventricose,  and  without  any  spines  or  protube- 
rances; the  spire  also  is  so  small  and  depressed,  that  the 
shell  has  very  much  the  appearance  of  a  Bulla,  length- 
ened out  at  the  base;  and  there  is  little  or  no  indica- 
tion of  even  the  thin  glazing  which  forms  the  inner  lip: 
such,  at  least,  are  the  characters  of  the  typical  species  *, 
which  are  few  and  easily  recognised.  In  P.  caudataj, 
a  new  modification  of  form  begins  to  be  developed, — 
slightly,  indeed,  but  quite  sufficient  to  leave  us  in  no 
doubt  as  to  the  characters  of  the  next  genus :  this 
species  has  the  general  form  of  Ficula,  but  the  spire  is 
somewhat  more  elevated,  and  the  inner  lip  is  so  much 
developed  that  it  begins  to  have  a  defined  margin  at  its 
lower  part  ;  the  body-whorl  loses  nothing  of  its  ventri- 
cose  or  inflated  aspect ;  and  the  shell  is  remarkably 
thin  and  brittle.  It  is  a  fact  highly  interesting  to  our 
present  purpose,  that  there  is  a  shell  in  almost  all  re- 
spects similar  to  the  Ficula  caudata  (of  which  it  has 
been  described  as  a  variety),  but  which  has  a  decidedly 
short  canal.  Here,  then,  is  the  point  of  junction  so 
desirable  to  be  established  between  Ficula  and  our  new 
genus  Rapella,  typically  represented  by  the  Ficus  rapa 
of  authors.;];  The  spire,  although  pointed,  is  still  re- 
markably short,  and  almost  turbinated  ;  the  body-whorl 
equally  ventricose  with  the  last,  but  the  lower  portion 
is  no  longer  lengthened  —  it  becomes  very  short,  and, 
by  the  more  sudden  contraction  of  the  aperture  at  the 
basal  point,  the  canal  becomes  so  very  small  as  almost 
to  be  obsolete.  From  the  absence  of  the  inner  lip  in 
the  last  two  genera,  the  shells  have  no  umbilicus,  but  in 
Rapella  both  these  characters  are  apparent  ;  the  umbi- 
licus is  usually  very  large,  while  the  base  of  the  inner 
lip  is  partially  or  entirely  reflected  over  it.  The  sub- 
stance of  these  shells  varies  according  to  the  species,  and 

*  Pyrulaficus  Lam.   Ency.  Meth.  pi.  431.  fig.  1.;  fig.  2.  is  another  species, 
t  Ency.  Meth.  pi.  436.  fig  1.  c.  X  Ibid.  pi.  434.  fig.  1. 

G    3 


86 


SHELLS    AND    SHELL-FISH.  PART   I. 


each  presents  a  graduated  link  between  the  thin  and 
brittle  Ficula  papyracea  and  the  strength  and  solidity  of 
the  other  types.  The  whole  of  the  Ficula  are  smooth, 
except  one  species  *,  which  has  some  very  slight  tubercles ; 
but  in  Rapella,  these  tubercles,  where  they  exist,  begin 
to  put  on  that  foliated  structure  so  prevalent  in  the  next 
genus  ;  and  in  others  there  are  indications  of  longitu- 
dinal plaits  upon  the  body  whorl :  the  outer  lip,  how- 
ever, is  still  very  thin,  and  the  whole  may  be  described 
as  a  group  of  generally  smooth  shells :  in  one  or  two 
species,  the  inner  lip  is  so  much  developed  at  its  base,  as 
actually  to  fill  up  and  cover  the  umbilicus.  Yet,  in  all 
the  variations  we  have  enumerated,  the  chief  generic 
characters  are  constant,  and  the  basal  canal  is  always 
small. 

(74.)  We  now  come  to  the  fourth  type,  or  the  genus 
Myristica, — a  name  we  exalt  from  a  specific  to  a  generic 
signification  for  the  shell  now  known  as  the  Pyrula  my- 
ristica, and  which  we  shall  here  call  Myristica  coronata. 
These  are  the  most  dissimilar  from  the  typical  groups 
we  have  yet  noticed :  the  form  indeed,  somewhat  pear- 
shaped,  —  inasmuch  as  the  spire  is  not  longer  than  the 
contracted  part  of  the  aperture,  from  which  the  canal 
may  be  said  to  commence  ;  but  they  have  nothing  of 
the  lightness  or  the  basal  elongation  of  Pyrula  and 
Ficula,  or  of  the  effuse  aperture  and  contracted  chan- 
nel of  Rapella.  They  may  thus  be  described  as  very 
short,  strong,  fusiform  shells  _;  the  umbilicus  either 
entirely  or  partially  concealed ;  the  outer  surface  armed 
with  muricated  and  semi-foliaceous  spines,  and  marked 
with  transverse  striae  ;  the  inner  lip  vitreous,  but  thin  ; 
the  outer  lip  with  an  ascending  channel  above,  and  a 
wide  and  distinct  one  at  the  base.  Now,  between  this 
and  the  last  group  there  is  a  series  of  connecting  links 
which  unite  them  in  the  most  perfect  manner  to  each 
other ;  few  of  them,  however,  are  figured  in  the  more 
general  conchological  works.  We  may  here  remark, 
that  the  P. hippocastanum  and  lineatai  of  Lamarck  are 

*  See  Sowerby's  Genera.  f  Ency.  Meth.  pi.  432.  fig.  4, 5.  . 


CHAP.  Ill,  THE    PYRULIX^.  8/ 

typical  examples  of  Myristicn;  while  the  well-known  Pij^ 
Tula  melongina,  from  having  a  much  wider  aperture^  puts 
on  something  of  the  characters  of  Rapella.  There  are, 
in  fact,  many  other  species ;  but  of  our  last  genus  Cuma 

there  is  only  one  that  we  are  yet 
acquainted  with,  which  can  be 
termed  truly  typical :  this  we  have 
named  C.  sulcata  {Jig.  4.).  Its 
characters  may  be  simply  de- 
scribed as  shorter,  but  more  gra- 
dually fusiform,  than  the  last,  — 
the  middle  of  the  pillar  being 
crossed  by  a  single  transverse  and 
very  prominent  fold :  this  cha- 
racter is  altogether  without  pa- 
rallel in  this  sub-family  ;  and  dis- 
tinguishes this  type,  at  the  first  glance,  from  all  the 
others :  the  form  of  the  shell  is  much  more  slender 
at  its  two  extremities  than  any  of  the  Myristicce,  and, 
although  much  shorter,  its  aspect  at  once  reminds  us 
both  of  Fusus  and  of  Plicatella.  Nevertheless,  although 
this  shell,  from  having  a  distinct  plait  upon  the  pillar, 
seems  to  us  the  true  type  of  the  connecting  genus  be- 
tween Pyrida  and  Fusus;  it  is  quite  evident  that 
the  common  Pyrula  carnaria  *,  and  the  more  rare  P. 
canaliculata  Sw.  t,  so  closely  agree  wdth  the  foregoing 
definition,  that  but  for  their  smooth  pillar,  and  the 
greater  elongation  of  their  base,  they  would  both  enter 
into  the  same  genus.  In  one  point  of  view,  it  may  be 
said  that  these  very  characters,  which  preclude  their  ad- 
mission into  Cuma,  may  yet  bring  them  wathin  the  con- 
fines oi Pyrula;  so  that,  being  followed  by  such  shells  as 
P.  carica  ^,  Sec,  we  come  again  to  the  typical  genus  with 
which  we  began  the  series ;  and  yet,  on  the  other  hand, 
we  may  suppose  these  dubious  species,  to  form  the  first 
genus  of  the  FusincB,  connecting  that  sub-family  with 
the  PyrulcB  by  means  of  Cuma.    In  either  way,  however, 

*  Ency.  Meth.  pi.  424.  fig.  3.  t  Ibid.  pi.  424.  fig.  2. 

X  Ibid.  pi.  433.  fig.  3. 

G    4 


88  SHELLS    AND    SHELL-FISH.  PART  I. 

there  is  abundant  evidence,  even  if  these  species  are 
omitted,  that  the  PyruUnce  form  a  circular  group,  in 
which  scarcely  a  link  is  wanting.  This  will  be  more 
evident  upon  arranging  the  whole  of  the  genera  in  a 
tabular  form,  and  placing  the  few  species  we  have 
already  named  in  the  natural  series  of  their  succes- 
sion. 


Genera  of  the  Pyrulinje. 

List  of  the  Species,  sJiowing  the  progressive  Change  of  one  Genus  to  the 

other. 

"tuba.    Ency.  Meth.  pi.  426.  fig.  2, 
perversa.     lb.  fig.  4. 

candelabrum.     lb.  pi.  437.  fig.  3.  ;  pi.  438,  fig.  3. 
Pyrula  <|  carina.     lb.  pi.  433.  fig.  3. 

canaliculata.     lb.  pi.  436.  fig.  3. 
spirata.     lb.  pi.  433.  fig.  2. 
_Burdigalensis.     Sowerby's  Genera,  fig.  2. 

rtricarinata.     lb.  fig.  3. 
T?,r„T  A  3  fi«^"s-     Ency.  Meth.  pi.  432.  fig.  1. 

ricuLA  ■)  reticulata  ia?«.     lb.  pi.  432.  fig.  2. 

tcaudata     lb.  pi.  436. 


Rapella 


Tpapyracea.  lb.  pi.  436.  fig.  1. 

3  abbreviata.  lb.  pi.  426.  fig.  2. 

ieffusa  Sw.  lb.  pi.  434.  fig.  1.  {Pyrula  Rapa.) 

C  nerito'ides.  lb.  pi.  435.  fig.  2. 


Smelongina.    lb.  pi.  435.  fig.  3.  a. — d. 
lineata.     lb.  pi.  432.  fig.  5. 
coronata  Siv.     lb.  pi.  432.  fig.  3.  a,  b. 
hippocastanum.     lb.  pi.  432.  fig.  4. 

CuMA  sulcata  Siv. — followed  by  Pyrula  tuba.  Sec. 

(75.)  The  strong  resemblance  of  the  Pyrulince  to 
the  PurpurincB  is  a  constant  subject  of  remark  among 
conchological  writers,  and  is  so  strong  as  to  be  often 
exceedingly  perplexing.  We  now  allude  only  to  the 
latter  group,  as  left  by  Lamarck  ;  but  many  of  these  are 
so  like  our  genus  Myristica,  that  it  is  only  upon  close 
inspection  their  distinguishing  characters  are  detected. 
Now,  this  strong  resemblance  can  be  accounted  for  in 
two  ways  :  first,  by  supposing  that  the  two  groups  re- 
present each  other  generally  in  their  own  respective 
circles  ;  and  secondly,  that  this  strong  analogy  actually 
extends   to  the  particular  genera  of  each   sub-family. 


CHAP.    III. 


THE    FUSINiE. 


89 


The  best  way,  therefore,  of  testing  this  theory,  is  to 
place  these  groups  in  separate  columns^  and  to  examine 
the  result. 

Analogies  of  the  Turbinellid^  and  the  C^ssid^e. 


Sub-families  of 
Turbine  llidcE. 

TURBINELLIN^. 

SCOLYMIN^. 

FUSININ^. 

Py  RULING. 


Eburnin^. 


Analogical  Characters. 

f  Shell  large,  ponderous,  heavy,  and  \ 
I     mostly  smooth.  j 

f  Shelis  rough,  muricated,  and  ge- 1 
t     nerally  spined.  J 

("Body  of  the  animal,  and  spire  of? 
i     the  shell,  excessively  long.         J 

Spire  always  shorter  than  the 
aperture;  the  pillar  straight  and 
smooth. 

Base  and  canal  very  short ;  inner  "^ 
lip  generally  formed  by  a  thick  ^ 
enamel.  3 


1 


I 


Sub-families  of 
MuricidcB, 

CASSINJi. 
MURICIN^. 

buccinin*. 
purpurin^. 

Nassin^. 


(76.)  Without  enlarging  upon  the  evident  traces  of 
a  systematic  series  of  analogies,  running  through  the  dif- 
ferent groups  here  brought  into  juxtaposition,  it  is  at 
once  seen  that  the  PyrulincB  and  the  PiwpurincE  actually 
come  opposite  each  other  :  and  having  already  shown 
(73.)  how  intimately  their  genera  correspond,  we  may 
pass  into  the  next  division. 

(77.)  The  Fusing  are  our  last  sub-family,  and 
are  composed  of  those  numerous  shells  arranged  in  the 
genus  Fusus  of  Lamarck,  and  are  the  most  elegant  and 
delicate  we  have  yet  noticed.  Their  general  form  is 
that  of  a  spindle,  tapering  very  much  at  both  extremi- 
ties :  hence  the  spire  is  very  long ;  and  as  this  contains 
the  body  of  the  animal,  the  circumstance  forms  a  ge- 
neric character,  both  for  the  moUusk  and  its  shell.  The 
canal  is  almost  invariably  long,  and  generally  equals 
the  spire,  while  the  basal  volution  is  typically  small : 
the  pillar  is  constantly  destitute  of  any  appearance  either 
of  plaits  or  teeth,  and  the  tip  of  the  spire  is  acute  : 
this  latter  character,  more  especially,  separates  them 
from  the  Turhinellince,  where  there  are,  in  the  aberrant 


90  SHELLS    AND    SHELL-FISH.  PART   I. 

genus  Clavalithes  Sw .* ,  several  shells  of  an  equally  fusi- 
form shape^  but  having  the  tip  of  the  spire  papillary. 
The  shape  of  the  FusincF,  and  the  elongation  of  the  body^ 
render  them  very  distinct  from  the  PyruUncB,  excepting 
at  that  point  of  junction  where  the  two  groups  are 
united.  Nothing  satisfactory  is  known^  so  far  as  we  can 
discover,  of  the  general  nature  of  the  animals. 

(78.)  The  Fusinm  being  thus  defined  as  a  whole,  we 
may  now  proceed  to  the  series  of  the  genera,  and  their 
peculiarities.  —  1.  In  the  first  or  typical  genus  Fusus, 
the  spire  and  channel  are  both  very  much  lengthened_, 
and  remarkably  slender ;  the  outer  lip  generally  cre- 
nated, — the  indentations  corresponding  with  the  internal 
striae,  —  2.  Chrysodomus,  distinguished  from  the  last  by 
the  comparative  shortness  of  the  basal  channel_,  and  the 
ventricose  or  enlarged  shape  of  the  body-whorl.  The 
beautiful  orange  mouthed  wilk  of  England  is  a  typical 
example ;  and  the  few  others^  now  known^  are  all  of  a 
large  size,  and  chiefly  found  in  northern  seas_,  where  they 
represent  the  more  elegant  Fusci  of  tropical  latitudes  : 
the  outer  lip  is  always  thin  and  smooth. — 3.  Leiostonms, 
where  the  body -whorl  is  still  larger  than  the  last,  while 
the  spire,  although  remarkably  short,  is  acutely  pointed  ; 
the  inner  lip  is  highly  polished,  and  the  contracted  base 
of  the  shell  is  equal,  or  rather  longer  than  the  aperture  ; 
the  outer  lip,  like  that  of  Chrysodomus,  is  thin  and 
sharp,  but  thickened  within.  All  the  species  of  this 
form  we  have  yet  seen  are  fossil,  of  which  the  Fusus 
bulbiformisf  is  one  of  the  best  and  most  common  types: 
the  outside  and  the  mouth  of  these  shells  are  always 
smooth  ;  hence  their  generic  name. — 4.  The  next  genus 
we  have  named  Strepsidura,  from  the  twisted  shape  of 
its  tail  or  channel :  the  form  of  these  shells  is  very  much 
like  the  last,  but  the  base  or  channel  is  equal  with  the 
spire,  and  is  turned  in  an  oblique  direction;  the  outside 

*  We  had  originally  called  this  genus  ClnveUa  ;  but  as  this  name  may  be 
thought  too  closely  resenihling,  in  sound,  those  of  ClavagcUa  and  Clavalula 
(Lamarck),  we  now  substitute  another,  —  more  appropriate,  indeed,  as  all 
the  species  we  have  yet  seen  are  fossil. 

t  Ency.  Mcth.  pi.  428.  fig.  3. 


CHAP.   III.  THE    FUSING.  Q\ 

also  is  marked  by  distinct  longitudinal  ribs^  and  has  a 
coronated  row  of  little  mucronate  spines^  much  like 
those  of  the  harps  :  the  type  is  the  Fusus  ficulneus,  a 
fossil  of  Grignon.* — 5.  and  lastly^  we  come  to  those  large 
species  represented  by  Fusus  colossus,  coronatus,  3forio, 
Szc,  which  we  have  arranged  in  the  genvis  Hemif us  us  j 
they  are^  indeed^  only  half  fusiform_,  as  the  spire  is 
shorter  than  the  aperture  :  they  are  also  distinguished 
by  an  internal  canal^  and  the  whorls  are  coronated  with 
compressed  spines  :  it  is  easy  to  perceive,  by  the  very 
aspect  of  these  shells,  that  they  form  the  passage  to  the 
Purpurce  ;  and  their  relation  is  so  close,  that,  until  we 
know  something  of  these  animals,  we  feel  somewhat 
uncertain  as  to  the  station  of  such  species  as  carnaria 
and  Cochlidium.  Hemifusus,  thus  standing  betAveen 
Strepsidura  and  Chrysostomus,  completes  the  circle  of 
the  FusincB. 

(79-)  Upon  taking  a  general  view  of  these  shells, 
w^e  cannot  but  observe,  notwithstanding  all  their  modi- 
fications, that  the  predominant  characters  of  the  group, 
more  or  less,  are  preserved.  In  all  of  them  we  find 
shells  more  or  less  —  equally  or  unequally  —  fusiform  ; 
that  is,  their  thickest  part  is  in  the  middle,  and  their 
two  extremities  attenuated  to  a  point.  No  teeth,  either 
marginal  or  internal,  are  ever  seen  on  the  outer  lip, 
while  the  inner  is  invariably  smooth  :  the  spire,  except  in 
one  type,  is  always  longer  than  the  basal  canal;  whereas, 
in  the  PyrulmcB,  the  very  reverse  of  this  takes  place. 
It  has  often  been  remarked  by  our  leading  zoologists, 
—  and  we  have  repeatedly  illustrated  the  truth  of  the 
position, — that  no  groups,  whether  generic  or  otherwise, 
are  so  natural  and  so  demonstrable  as  those  which  are 
linked  to  others  by  mtervening  gradations  of  form. 
This  is,  indeed,  completely  opposed  to  the  old  opinion 
formerly  entertained,  that  no  such  divisions  should  be 
tolerated  in  systems,  but  such  as  were  distinctly  separated 
from  each  other;  or,  in  other  words,  that,  so  soon  as  the 

*  The  Fusus  heptagonus    (Ency.  Mdth.  pi.  428.  fig.  7.)  probably  belongs 
also  to  this  genus,  —  although  as  an  aberrant  species. 


92 


SHELLS    AND    SHELL-FISH. 


PART  I. 


links  which  connected  two  genera  were  discovered,  the 
two  should  be  thrown  into  one.  Experience,  however, 
setting  aside  all  other  considerations,  has  long  ago  con- 
signed this  dogma  to  oblivion,  and  has  even  obliged  its 
warmest  advocates  to  renounce  it.  Ever^  day,  almost, 
is  bringing  before  us, — particularly  in  the  invertebrate 
animals, — not  only  forms  altogether  new,  but  such  modi- 
fications of  those  we  already  have  in  our  collections, 
that  in  a  few  years  we  may  fairly  anticipate  not  one  in 
ten  of  the  testaceous  genera,  now  apparently  isolated, 
will  remain  so  ;  the  links  which  unite  them  to  others 
will  be  discovered  ;  and  thus,  had  we  continued  to  unite 
one  geims  to  another  in  the  fashion  above  adverted  to, 
we  should  be  now  fast  approaching  that  simplicity  of 
nomenclature  which  would  class  all  shells  under  one 
genus, —  the  genus  Testacea.  It  is  only  by  following 
out  a  theory  of  this  sort,  and  seeing  to  what  it  would 
lead  in  a  general  and  extended  application,  that  we  can 
judge  of  its  philosophic  soundness  or  of  its  practical 
utility. 

(80.)   All    the   types  of  the  FusirKP,  as  will  now  be 
shown,  have  their  representatives  in  the  PyruUiKE. 


Analogies  of  the  Fusing  and  the  Pyrulin^e. 


Genera  of  the 

Fusing. 

Hemifusus. 

Fusus. 

Chrt/folomus. 

Leiostomjis. 

Strepsidura. 


Analogies. 

C Trapeziform,     or    sub-fusiform;? 
t     channel  short.  j 

C Channel    remarkably  long;    the 7 
\     whorls  generally  angulated.        j 

Channel  moderate. 

f  Spire  very  short ;  the  basal  whorl") 
I     large  and  ventncose.  3 

The  base  of  the  pillar  slightly'^ 
turned  outward,  the  exterior  > 
rougli  and  mucronate.  j 


I 


Genera  of  the 
Pyrulin^. 

Cu7na. 


Pyrula. 

Ficula. 

Rapella. 

Myristica. 


The  first  of  these  resemblances,  or  that  between 
Hemifusus  and  Cuma,  is  obviously  an  affinity,  since  the 
most  inexperienced  student  can  perceive  that  these  two 
groups  pass  into  each  other.     The  greatest  elongation 


CHAP.   III.  ANALOGIES    OF    THE    FUSING.  QS 

of  the  basal  channel  takes  place  among  the  Fusince  in 
Fusus,  and  the  like  character  among  the  Pyrida  in  the 
opposite  column  ;  while  in  Chrysodomus  and  Ficula 
this  part  is  but  of  moderate  length.  Strepsidura  is 
the  only  genus  in  the  first  column^  which,  by  its  lon- 
gitudinal plaits  and  prickly  tubercles,  corresponds  to 
Myristica  ;  while  the  inflated  shape  of  Leiostomus  im- 
mediately reminds  us  of  Rapella  —  its  prototype  among 
the  PyruUnce. 

(81.)  Before  taking  leave  of  the  Fusince,  it  will  be 
interesting  to  ascertain  how  far  the  genera  put  on  the 
aspect  of  those  composing  the  TurhinellincB,  more  par- 
ticularly as,  the  former  being  the  last,  and  the  latter  — 
TiirhineUincB — the  first  with  w^hich  we  commenced, 
it  foUows,  as  a  necessary  consequence  of  the  circularity 
of  the  whole  family,  that  these  two  divisions  join,  and 
blend  into  each  other.  This,  we  think,  will  be  very 
evident,  upon  examining  the  following  table  :  — 

Analogies  of  the  Turbinellin^  and  the  FusiNiE. 

i    Genera  of  the  .    ^^„;„„.„  Genera  of  the 

TuRBiNELLii.  Analogies.  Fusing. 

Turbmella  IjaTa.      Typical  of  their  respective  groups.  Fusus. 

?  Sub-typical.  Chrysodomus. 

i-^-.^,-,/      „  T  ovv,     CTrapeziform;  the  whorls  turreted:  7  rr      -^ 

Fasciolaria  l.a.m.   y     canal  moderate.  j         Hetmfusus.      . 

X,,,     ,.  fPyriform ;  the  canal  long;  the  base7  o,         j 

Pyrella.  ^     of  the  pillar  turned  inward.        j         Strepsidura. 

r  Remarkably    smooth  ;   the    spireT 
Clavalithes.  <     and  aperture  of  equal  length  ;  >■        Leiostomus. 

L     the  pillar  straight.  3 

(82.)  It  would  hardly  be  necessary  to  repeat,  in  this 
place,  the  fact  we  have  so  often  adverted  to  and  illustrated 
in  former  volumes,  regarding  the  analogies  of  typical 
gi'oups,  were  it  not  highly  probable  that  they  have  not 
met  the  eye  of  our  conchological  readers.  It  is  there- 
fore, perhaps,  necessary  to  apprise  them,  that  the  re- 
semblances between  the  typical  divisions  of  two  groups, 
when  thus  brought  into  comparison,  are  almost  always 


^4*  SHELLS    AND    SHELL-FISH.  PART  I. 

more  remote  and  faint  than  those  which  relate  to  the 
aberrant  divisions^  —  and  for  this  simple  reason;  —  the 
typical    groups    are    furthest    apart    from   each   other ; 
while  the   aberrant  ones,  by  which  they  are   connected, 
are    consequently  nearer.     In   this  branch  of   science, 
moreover,  the    difficulty   of   discovering   the   analogies 
of  typical  groups  is  still  further  increased,  when,  as  in 
the  present  instance,  we  are  without   that  precise   in- 
formation on  the  animals,  which  might  furnish  us  with 
some    analogical    points    of   resemblance.     Besides,    it 
must   always  be  borne  in  remembrance,  that  our  ar- 
rangement is  not  built  upon   these  analogical  compa- 
risons,  but  upon   absolute  or   presumed  affinities,  the 
result    of   minute    analysis.       Whatever    coincidences, 
therefore,  arise  on  comparing  the  different  groups,  are 
more  properly  the  result  than  the   cause  of  their   ar- 
rangement.    Analogy  is  thought  to  be  of  the  highest 
importance  for  the  verification  of  a  natural  group,  but 
it  must   always  be  subordinate  to  affinity.     Applying 
these  general  remarks  to  the  two  typical  groups  which 
stand  first  upon   our  list,  it   will  be  remembered  that 
one,  intervening   between    Turbinella  and  Fasciolaria, 
has  never  been  made  known.      Passing  these,  however, 
and  comparing  Fasciolaria  and    Hemifusus,  we    find 
they  are  almost  precisely  of  the  same  shape  and  pro- 
portions ;  and  that  the  shells  can  only  be  distinguished  by 
one  having  the  pillar  plaited,   and    the  other  smooth. 
The  very  name  of  ficulneus,  given  by  authors  to  the 
type  of  Strepsidura,  shows  its  analogy  to  Pyrella,  and 
consequently  to  Fyrula  ;  it  is,  in  fact,  completely  a  pear- 
shaped    shell.       The    resemblance    of    Clavalithes    and 
Leiostomvs  is  equally   striking  :    both  are  remarkably 
smooth   shells  ;   with  the  channel  lengthened,  and  the 
basal  volution  more   or  less  enlarged  ;    both  are  fossil 
genera  of  the  same  strata;  and  although  Clavalithes  in 
general  possess  very  small  plaits   on    the  pillar,  and  a 
papillary  spire  (without  which,  in  fact,  the  genus  could 
not  be  clearly  defined),  yet  there  are  one  or  two  species 
having  the  pillar,  as  in  Leiostomus,  perfectly  smooth. 


CHAP.   III.  MURICID^    AND    TURBINELLID^.  9^ 

If  the  reader  turn  to  the  figures  of  Clavalithes  longcevus, 
clavellatus,  scalaris,  Noce^  and  rugosus*,  and  to  that  of 
Leiostomiis  hulhiformis  f,  he  will  at  once  perceive  their 
mutual  affinity  much  better  than  from  our  description. 
(83.)  Having  now  supplied  all  the  details  in  our 
power  respecting  the  two  great  families  of  the  Zoophaga, 
or  predacious  shell-fish, —  and  which,  in  fact,  stand  at 
the  head  of  the  entire  class  of  Test  ace  a, — we  shall 
lay  before  our  readers  the  following  diagram,  which 
will  explain,  more  distinctly  than  our  usual  tables,  the 
circular  affinities  of  each  of  these  families,  and  the  cor- 
responding analogies  of  their  sub-families. 


1  M,iricinw/6- =^-^\ -/- <>sTurbinina!  \ 


2  Casshvt^ j\- 'Cj  Scolymincs  2 

4  Purpurincei 

3  Nassin^O^^^ ^^^^hurnirue  3 

The  analogies  of  the  two  typical  sub- families  (Land 
2.)  of  the  circles  are  very  remarkable.  We  thus  find  that 
the  MuricincE  stand  opposite  to  the  TurhinincB,  and  the 
Cassince  to  the  ScoIymirKe.  These  resemblances  repose 
on  the  relative  developement  of  that  portion  of  the 
shell  which  protects  the  respiratory  siphon  (which 
must  of  course  be  modified  in  unison  with  its  covering 
or  sheath)  :  thus,  in  the  MuricincE  and  the  Turhinince, 
the  basal  canal  is  considerably  longer  than  in  the  Cassinm 
and  the  Scolymince,  where,  in  effect,  this  part  is  either 
short,  or  absolutely  wanting.  Thus  it  is,  that  we  may 
often  overlook,  or  be  ignorant  of,  some  one  character, 
which,  when  discovered,  serves  as  a  common  bond  of 
analogy  between  two  groups,  in  all  other  respects  to- 
tally different. 

*  Ency.  Meth.  pi.  425.  f  Ibid.  pi.  428.  fig.  1.  a,  b. 


()6  SHELLS    AND    SHELL-FISH.  PART  I. 

(84.)  The  genus  Buccinum  andthe  aberrant  genera  of 
Fusus  are  so  much  ahke,  that  they  can  only  be  distin- 
guished by  the  latter,  as  Chrysodomus,  having  the  basal 
canal  slightly  produced  instead  of  truncated.  These  two 
divisions  are  further  remarkable  for  containing  those 
genera  which,  by  the  length  of  their  spire,  contain  the 
longest-bodied  Testacea  in  the  whole  tribe.  But  for 
its  elongated  canal,  Fusus  colus  and  its  allies  would 
become  TerehrcB  ;  while,  but  for  their  truncated  base, 
these  latter  would  be  placed  among  the  Fusince.  The 
remarkable  analogies  between  the  PurpurincB  and  the 
Pyrulincp.  (4.  4.),  having  already  been  so  much  enlarged 
upon,  need  not  be  again  repeated.  The  only  remaining 
comparison  concerns  the  EburninfS  and  the  Nassince, 
— 'two  groups  so  closely  related  to  each  other  in  their 
typical  examples,  that  even  Lamarck,  mistaking  ana- 
logy for  affinity,  actually  places  them  following  each 
other  :  both,  in  fact,  have  the  base  of  the  shell  obtuse, 
without  any  elongation ;  the  inner  lip  very  thick,  and  a 
strong  internal  groove  within  the  aperture.  But  it  is 
needless  to  insist  upon  an  analogy  so  indisputable  :  we 
may,  therefore,  presume,  that  in  these  two  comprehensive 
groups  we  have  made  good  all  our  propositions  on  the 
laws  of  the  natural  system  * ;  and  we  shall  now  endea- 
vour to  do  the  same  in  the  succeeding  families  of  the 
Gasteropoda. 

*  The  Geography  and  Classification  of  Animals^  Part  iii.  On  the  First 
Principles  of  natural  .Classification,  p. ,221.  Vol.  LXVl.  of  the  Cabinet 

CvCLOPJiDlA. 


97 


CHAP.  IV. 

THE   ZOOPHAGA,  OR    PREI>ACEOUS    SHELL-FISH,   CONTIN'UEn. THE 

FAMILY    OF    VOLUTIDiE,    OR    VOLUTES. 

{85.)  We  now  come  to  one  of  the  most  interesting 
and  beautiful  families  of  the  spiral  Testacea;  whether  in 
regard  to  the  elegance  of  the  shells  themselves,  or  as 
exhibiting  a  principle  of  variation  in  their  structure 
which  can  hardly  be  excelled.  Our  knowledge  of  the 
animals  themselves  has  been  much  increased,  of  late 
years,  by  the  French  naturalists,  and  by  the  exquisite 
drawings  of  Guilding.  To  generalise  these  discoveries, 
however,  so  as  to  assign  some  undeviating  character  to 
the  whole,  is  almost  impossible.  The  only  peculiarity 
appears  to'  be  the  absence  of  any  operculum  :  in  the  ma- 
jority, the  eyes  are  sessile,  placed  at  the  base  of  two 
short  tentaeula,  and  as  much  developed,  in  the  typical 
volutes,  as  they  are  in  the  Stromhidcs :  the  mouth  is 
probosciform  and  extensile ;  and  the  foot,  in  the  typical 
group,  of  enormous  size. 

(86.)  The  shells,  however,  present  us  with  more 
tangible  characters.  The  base  is  never  prolonged  ; 
although  in  some  mitres  {Tiara)  it  is  contracted:  in 
all  others  it  is  truncated,  as  in  the  BuccinincB,  and 
deeply  notched.  The  truncated  base  at  once  separates 
this  family  from  the  Turhinellince,  as  there  is  no  in- 
stance of  a  volute  with  an  elongated  channel.  The 
plaits  upon  the  pillar,  again,  are  always  at  the  base  — 
not  in  the  m.iddle  only  —  of  the  aperture  ;  although,  in 
the  aberrant  groups  of  Oliva,  Ancillaria,  and  Marginella, 
they  assume  peculiar  modifications.  The  proportion  of 
the  spire  to  the  aperture  varies  in  almost  every  genus ; 

H 


9S 


SHELLS    AND    SHELL-FISH. 


PART   I. 


and  is,  therefore,  but  a  subordinate  character.  Nume- 
rous as  is  this  family,  nearly  all  the  species  are  confined 
to  warm  latitudes,  particularly  those  of  the  tropics.  It 
is  hardly  necessary  to  add,  that  the  whole  are  predaceous, 
and  consequently  carnivorous. 

(87.)  The  VoLUTiD*:  arrange  themselves  into  five 
primary  groups.  —  1.  The  Volutins,  or  typical  vo- 
lutes, having  a  short  spire  more  or  less  papillary,  and 
the  lower  plaits  upon  the  pillar  largest ;  the  foot  is 
excessively  large,  and  envelopes  the  sides  of  the  shell. 
2.  The  Mitring,  or  mitres,  where  the  spire  is  always 
acute,  generally  longer  than  the  aperture,  and  the  lower 
plaits  smallest ;  the  foot  small,  not  dilated  on  the  sides, 
and  the  siphon  (a)  rather  long,  as  in  Mitra  sanguisuga. 


(Jig.  5.)  The  first  is  the  typical,  and  the  second  sub- 
typical.  The  three  aberrant  sub-families  are,  —  3.  The 
CJLiviNiE,  or  olives :  cylindrical  in  shape  ;  the  aperture 
linear,  and  the  pillar  thickeijed  and  confusedly  plaited. 
4.  Ancillaria  :  the  aperture  wide,  and  the  base  of  the 
pillar  alone  thickened  and  striated.  5.  The  Marginel- 
jAtiJE,  or  date-shells,  having  plaits  upon  the  pillar,  and 
crenated   teeth   on  the    thickened   outer  lip ;    the   foot 


CHAP.   IV.       PRIMARY  DIVISIONS,   THEIR  ANALOGIES.      99 

very   large,    but    the   mantle    not    lobed    or    reflected. 

{fig^  6.)* 

(88.)  These  primary  divisions  having  long  been  ad- 
mitted by  all  writers,  we  shall  at  once  compare  them 
with  those  of  the  predaceous  Zoophaga. 


Analogy  of  the  Volutid.e  and  the  Zoophaga 

Analogies. 


Sub-families  of  the 
Voiutidte. 


Families  of  the 
Zoophaga. 


VOLUTINA. 

MlTRIX^. 
OLIVINiE. 

Ancillarin^, 
Marginellin^. 


[ 


Foot  of  the  animal  excessively 
large ;   base  of  the  shell  trun 
cate, 

{Volutince  and  Cassin^.) 


■•} 


Foot  small,  not  so  long  as  the'J 
shell,  the  base  of  which  is  con-  r 
tracted.  J 

{Mitrttus  and  Scolymus.) 

f  Spire  very  short ;  tip  papillary  j  1 
X     pillar  plaited.  J 


Spire  nearly  or  quite  concealed. 
Outer   lip  detached  and    thick- 


{ 


ened. 


] 


Muricidce. 

Turbinellidis. 

I'olutid^. 

Ci/prceidee. 

Strombidce. 


Thus,  the  truncated  and  wide-mouthed  helmet-shells, 
among  the  MuricidcE,  find  their  prototypes  in  the  melon 
volutes  ;  and  the  muricated  mitres,  in  the  sub- typical 
Turhinellida;,  with  which  they  also  agree  in  their  fu- 
siform shape.  The  Olivines  correspond  to  the  typical 
volutes,  in  having  their  foot  excessively  large.  The  ani- 
mal of  Ancillaria  is  unknown  ;  but,  from  the  high  polish 
of  the  shells,  we  may  suppose  it  is  analogous  to  the 
cowries.  Lastly,  the  3Iarginellincp  are  clearly  proto- 
types of  the  Stromhid<T,  as  they  are  the  only  volutes 
which  have  the  top  of  the  outer  lip  detached  from  the 
body-whorl, 

(89-)  The  weakest  point  in  the  foregoing  table  is 
that,  perhaps,  which  relates  to  the  Ancillarice  ;  but,  by 
comparing  the  family  with  the  Cassidce,  the  station  of 
this  group  will  be  more  clearly  shown. 

*  The  annexed  cut  is  from  one  of  the  unpublished  drawings  of  Guildinj: 
the  shell  is  jiure  white. 

H     2 


100 


SHELLS    AND    SHELL-FISH. 


PART   J. 


Analogies  of  the  Volutid^  and  the  Cassid^e. 


Suh-iamilies  of 

VoLirrii)-E. 
Tyjjical  Genera. 

VOLUTA. 
MlTRi. 

OUVA. 
AjfCILLiRIA. 

Marginella. 


Analogical  Characters. 

Smooth;  spire  short ;  base  truncate. 
f  Rough  ;  spire  longer  j  base  atte-  1 
X     nuated.  i 

f  Foot  very  large  ;  no  distinct  plaits  > 
X     on  the  pillar.  3 

Aperture  very  wide  ;  the  base  of 
the  i)illar  oftea  thickened  and 
striated. 

J"  A   thick  deposition  surrounding 
t     the  anerture  of  the  shell. 


i 


Sub-families  of 

CASsin^. 
Typical  Genera. 

Cassis. 

MUREX. 

buccinum. 

Purpura. 

Nassa. 


This  table  illustrates  what  has  been  often  shown 
among  the  vertebrated  animals,  —  that,  to  establish  the 
analogies  of  two  given  groups,  they  must  often  be  traced 
through  the  medium  of  other  groups  :  thus,  the  Ancil- 
larice,  in  one  respect,  are  prototypes  of  the  Cyprcece;  and 
in  another,  by  their  wide  aperture  and  striated  base,  are 
equally  so  to  the  Parpum.  Again,  if  it  was  asked, — 
Vyhat  shells  among  the  volutes  have  a  marked  resem- 
blance to  Concholepas  and  Monocerob-  ?  every  natural- 
ist would  point  to  Ancillaria  ;  for  all  three  have  a  very 
wide  aperture,  and  a  distinct  prominent  tooth  at  the  base 
of  the  outer  lip.  This  is  conclusive  evidence  ;  and  it 
therefore  follows  that  the  analogy  betw^een  AncUkiriii 
and  Ci/pr(va,  however  obscure  in  a  direct  Avay,  is  ren- 
dered plain  by  being  traced  through  the  medium  of  the 
Furpurince.  The  other  analogies  in  the  table  are  so 
palpable  to  the  zoologist,  that  they  require  no  illustra- 
tion. Hence  it  follows,  as  a  natural  result  of  this  com- 
parison, that  the  Volutidcp,  in  like  manner,  represent 
all  other  of  the  circular  groups  in  the  zoophagous 
tribe. 

(90.)  Our  next  object  is  to  show  that  the  Volutidcp. 
as  a  whole,  form  a  circle  of  affinity.  It  is  clear  that  the 
pre-eminently  typical  volutes,  or  melon-shells,  branch 
off  into  two  separate  series  ; — one  leading  to  Scaphelhi, 
through  F.  magiiifica,  falgetruni,  papillaris,  and  fuai^ 


CHAP.   IV. 


CIRCLE    OF    VOLTJTID^. 


101 


form  is  ;  the  other  to  Cymbiola,  or  the  muricated  volutes. 
From  this  latter,  therefore,  we  shall  begin  to  trace  our 
circle ;  because,  even  here,  we  have  evidently  a  repeti- 
tion of  the  analogy  between  the  smooth  helmets  and 
the  spined  murexes.  After  the  Cymhiolce,  or  muricated 
volutes,  succeed  such  as  have  the  spire  elongated,  and 
the  plaits  upon  the  pillar  numerous  :  among  them  is  the 
Valuta  lyriformis  ;  and  this  brings  us  at  once  into  the 
sub-family  of  the  mitres  :  from  these  the  passage  to  the 
olives  is  rendered  so  gradual,  by  Mitvplla  in  one,  and 
Olivella  in  the  other,  that  the  mere  systematist  will 
hardly  admit  these  genera,  because  they  blend  into  each 
other.  Hiatula  is  in  the  same  predicament :  by  its  wide 
mouth,  and  the  thickened  base  of  its  pillar,  it  is  all  but 
an  Ancillaria;  so  that  the  junction  is  here  also  complete. 
There  remains,  then,  only  the  MarginellcE,  which  are  so 
like  some  of  the  AnciUarice,  that  we  may  safely  place 
them  as  next  in  the  series.  What  group  then  succeeds  } 
The  illustrious  Lamarck  considered  the  well-known 
/'^"A  ^'^oluta  Zebra  (Jig.  ?•  «)  of 
/'Pf  ^  our  catalogues  to  be  so  like  a 

(wmM\   Marglnella,  that  he  has  actually 

mim^  placed  it 


in  that  genus :  and 
l>\'  i  the  affinity  between  this  shell 
and  Scaphella  maculata  (6)  is 
immediate  :  we  thus  pass  to  the 
S.  fulgetrum,  and  again  reach 
the  typical  volutes.  Thus,  by 
a  different  route,  we  return  to 
the  point  from  which  we  started,  without  a  link  in  the 
chain  being  wanting. 

(91.)  We  have  thus  shown  that  the  VolutidtT  form 
a  perfect  circle  of  affinity  ;  and  that  the  divisions  we 
have  thrown  them  into  are  strictly  natural,  because  they 
are  prototypes  of  all  the  others  in  the  zoophagous  tribe. 
Each  of  these  primary  groups,  or  sub-families,  will  now 
be  examined  in  detail,  in  the  order  in  which  they  na- 
turally follow  j  viz.,  the  Volutins,  the  Mitring,  the 
Olivine,  the  AxciLLARiisriE,   and  the  Marginellin^.. 

H   .3 


a/^\S\ 


102 


SHELLS    AND    SHELL-FISH. 


PART  I. 


(92.)  The  VoLUTiNJE,  or  volutes,  are  immediately 
distinguished  from  the  mitres  by  being  more  ventricose 
shells,  with  a  much  shorter  spire  (as  in  Voluta  Ollu, 
fig.  8.),  the  apex  or  point  of  which  is 
more  or  less  thick  and  papillary.  These 
characters  are  developed  in  their  highest 
perfection  in  the  smooth  and  coronated 
melon-shells,  to  which,  as  being  the 
pre-eminent  types  of  the  whole  family, 
we  are  compelled  to  retain  the  sub-generic 
r\dimeoi  Voluta.  Nevertheless,  these  cha- 
racters are  greatly  modified  in  the  five 
leading  genera,  which  we  characterised 
and  illustrated  several  years  ago  ;  and  time  has  only  con- 
firmed us  in  the  views  we  then  took  on  the  subject.  We 
accordingly  arrange  the  whole  of  the  Lamarckian  volutes 
under  five  leading  genera.  1 .  Voluta,  —  having  the  spire 
excessively  short,  thick,  and  invariably  smooth ;  the 
suture  of  the  body-whorl  being  generally  covered  with 
a  vitreous  deposition  or  glazing,  never  seen  in  the  next 
genus.  2.  Cymbiola,  — having  the  body-whorl  less  ven- 
tricose, and  the  spire  longer  ;  the  apex  not  near  so  thick  ; 
while,  in  all  those  species  which  are  coronated,  the  whorls 
are  marked  with  tubercles.  In  both  these  groups,  the 
plaits  are  almost  invariably  four,  —  the  upper  ones  very 
thin  and  small,  while  the  lowest  is  nearly  double  their 
thickness.  This  structure  of  the  plaits,  it  may  be  here 
observed,  belongs  alone  to  these  two  typical  genera.  The 
third  genus  is  Harpula,  where  the  plaits  upon  the 
pillar  are  very  numerous,  —  the  upper  ones  remarkably 
slender,  but  gradually  increasing  in  size  and  thickness, 
until  the  last,  or  the  two  last,  which  suddenly  become 
smaller  :  the  terminal  whorls  of  the  spire,  although 
still  papillary,  are  much  more  slender.  The  form  of 
the  spire,  however,  undergoes  a  change  in  this  group, 
and  is  therefore  of  secondary  importance.  This  gra- 
dual diminution  of  one  of  the  typical  peculiarities  of 
the  Volutince  prepares  us  for  the  fourtli  genus,  Volii- 
tilithes,  where  the  apex  is  perfectly  regulai"  and  acute. 


CHAP.    rv.  CHARACTERS    OF    THE    GENERA.  103 

This  is  one  of  the  most  natural,  and,  at  the  same  time, 
interesting  groups ;  for  no  recent  species  has  yet  been 
found.  The  upper  and  finer  plaits  upon  the  pillar, 
so  characteristic  of  Harpula,  now  disappear,  and  leave 
only  one  or  two,  or  perhaps  three,  of  the  larger  ones 
at  the  base  :  the  number  of  these  plaits,  iti  fact,  varies 
according  to  the  proximity  or  the  remoteness  of  the 
species  to  Harpula.  The  general  shape  is  fusiform,  the 
whorls  being  strongly  coronated  with  spines,  and  often 
marked  with  transverse  elevated  ribs.  The  fifth  and 
last  genus  is  Scaphella,  where  the  upper  plaits  of  the 
pillar  are  as  large  as,  or  even  larger  than,  the  lower ;  the 
outer  lip,  also,  is  thickened  within,  and  the  suture  of 
the  whorls  is  covered  by  a  glazing  of  enamel.  All  the 
species  yet  discovered  are  smooth ;  and  from  the  high 
polish  with  which  many  are  covered,  there  is  every  rea- 
son to  believe  the  animal  has  a  strong  affinity  to  that  of 
Mnrginella:  this,  indeed,  is  so  obvious  in  the  shells  them- 
selves, that  Lamarck,  as  we  before  observed,  has  placed 
the  Scaphella  Zebra  (^jig.  ?•  «)  ii^  that  group.  The  form- 
ation of  the  spire  in  general  is  conic,  obtuse,  but  hardly 
papillary ;  but  in  certain  aberrant  shells,  as  S.  fusifor- 
mis  and  papillaris,  the  apex  becomes  thickened,  and 
assumes  all  the  characters  of  the  true  volutes,  and  thus 
unite  with  the  melons  by  means  of  V.  magnifica. 

(93.)  By  these  typical  characters,  it  appears  to  us 
that  the  natural  and  primary  divisions  of  the  La- 
marckian  volutes  are  regulated.  In  this,  and  all  similar 
investigations,  we  have  found  it  necessary  to  discard  all 
theoretical  notions  as  to  what  should  be  the  primary 
types.  No  ordinary  degree  of  impartiality  is  necessary 
for  accomplishing  this  ;  because  every  naturalist,  more 
or  less,  is  prone  to  form  certain  preconceived  notions  as 
to  what  he  thinks  should  he  the  types  of  any  particular 
family  ;  and  thus,  prejudiced  in  favour  of  some  hypo- 
thesis, he  sits  down  to  his  task,  exactly  in  that  frame  of 
mind  the  most  un suited  for  the  investigation  of  truth. 
We  candidly  confess  that  many  years  ago,  when  this 

H    4 


04 


SHELLS    AND    SHELL-FISH. 


PART  r. 


family  first  engaged  our  attention^  we  imbibed  a  notion 
that  the  formation  of  the  spire  was  the  chief,  if  not  the 
only,  character  upon  which  they  should  be  arranged  :  we 
soon,  however,  threw  aside  this,  and  fancied  the  same 
importance  attached  to  the  number  of  plaits :  equally  dis- 
satisfied with  this  theory,  we  finally  resolved  to  combine 
all  these  characters,  without  giving  to  any  one  a  para- 
mount importance  :  having  done  this,  we  soon  perceived 
that  these  groups  turned  out  to  be  representations  of  all 
those  in  the  entire  family  ;  and  this  discovery  prevented 
our  falling  into  many  errors,  which  would  otherwise 
have  been  inevitable.  We  may  now  consider  each  of 
these  genera  in  further  detail. 

(94.)  The  pre-eminent  types  of  the  genus  Voluta,  for 
reasons  subsequently  stated,  are  such  shell-fish  as  have  the 
spire  small,  and  so  slightly  developed,  as  to  be  all  but 
obsolete.  This  Ave  see  more  especially  in  Voluta  Nep- 
tuni,  Porcina,  and  Cymbium  {fig.  9*  ^)  where  nearly  the 


whole  shell  being  enveloped,  as  it  were,  in  the  body-whorl, 
gives  to  it,  in  all  but  the  plaited  pillar,  the  perfect  ap- 
pearance of  a  Bulla.  The  very  slight  elevation  of  the 
spire  is,  therefore,  one  of  the  typical  characters  of  this 
genus  ;  but  it  is  not  the  only  one :  the  spiral  whorls, 
which  end  in  the  apex,  whenever  they  are  developed, 
are  remarkably  thick,  and  are  always  perfectly  smooth, 
although  the  body-whorl  may  be  coronated ;  whereas  in 
the  next  genus,  Cymhiola  (C.  vespertilio,  fig.  9-  ^)»  these 
spiral  whorls  are  always  plaited  (c).    There  is  a  solitary 


CHAP.  IV.    TYPES  OF  THE  GENUS  VOLUTA.        105 

exception  to  this  form  in  the  true  volutes,  which  is  seen 
in  Voliita  angulata,  where  the  spire  is  absolutely  pointed: 
this  exception,  however,  is  a  necessary  one,  for  other- 
wise there  would  be  no  species  which  would  represent 
VolutiUthes.  The  exterior  of  all  these  shells,  so  far  as 
we  yet  know,  is  covered  with  a  thin  epidermis,  except, 
perhaps,  P.  prohoscidalis ;  so  that,  notwithstanding  the 
enormous  foot  of  the  animal,  it  does  not  appear  that  any 
part  of  the  shell  is  covered  by  that  member.  The  chief 
variations  among  those  shells  are  as  follows:  — First,  the 
melons,  whether  smooth  or  coronated.  Secondly,  the 
horned  volutes,  where  the  form  is  less  ventricose,  and 
the  body-whorl  armed  with  long  spines,  as  in  imperialis 
and  chrysostoma  *,  both  being  connected  to  the  coronated 
melons  by  Broderipia  and  marmorata.  The  third 
type  is  the  V.  Scaplia,  having  the  outer  lip,  as  in  the 
Stromhidce,  considerably  angulated  and  dilated.  The 
fourth  type  is  the  V.  angulata,  whose  aperture  is  very  ef- 
fuse ;  and  the  spire  very  short,  but  pointed.  Lastly  comes 
the  Voluta  magnificaandfulgetrum '[,  where  we  once  more 
have  the  egg-shaped  and  inflated  form  of  the  melons, 
together  with  their  very  thick  apex,  totally  different 
from  that  of  the  Voluta  ancilla,  Sec,  with  which  authors 
have  hitherto  placed  it.  The  Voluta  olla  and  ruhiginosa 
follow  this  type,  and  blend  it,  in  the  most  perfect  manner, 
with  those  we  first  enumerated. 

(95.)  The  passage  from  Voluta  to  our  next 
genus,  Cymbiola,  is  opened  by  the  rare  V.  mitis  of 
Lamarck ;  which,  by  its  general  smoothness,  its  thick 
spire,  and  a  slight  separation  of  the  top  of  its  outer  lip 
from  the  adjoining  whorl,  evinces  a  close  affinity  with 
V.  ScapJia.  The  volutes  now  before  us  differ  from  the 
former,  in  being  stronger,  less  ventricose,  and  having 
their  spire  much  more  lengthened  :  their  whorls  are 
angulated,  and  are  mostly  armed  with  acute  spines,  or 

*  Exotic  Conchology. 

f  "  In  size  and  form  this  shell  approaches  nearly  to  V.  magnifica."  — 
Tank.  Cat.  p.  28. 


10b'  SHELLS    AND    SHELL- FISH.  "PART   I. 

small  tubercles.  Their  great  distinction,  liowever, 
lies  in  the  apex  of  their  sj)ire,  which  always  exhibits 
the  incipient  developement,  in  the  shape  of  tubercles,  of 
those  spines  which  may  be  on  the  body- whorl.  The  com- 
mon Cymhiola  vespertilio(^fig.  9-  h)  is  the  type  of  the  whole 
genus.  From  these  to  the  next  division,  represented  by 
Cym.  pacifica,  gracilis,  &c.,  the  gradation  is  easy  and 
natural.  Nevertheless,  these  Australian  shells  constitute 
a  distinct  division ;  for  they  are  known  at  once  by  the 
greater  prolongation  of  their  spire,  which  is  nearly  equal 
to  their  aperture,  and  by  the  majority  being  only  tuber- 
culated :  the  apex  is  always  obtuse  and  slightly  papil- 
lary. Whether  we  should  con- 
sider the  V.  ancilla  (Jig.  10.) 
as  a  distinct  type  of  form,  is 
uncertain,  but  it  possesses  a 
peculiarity  of  aspect,  which 
seems  to  detach  it  from  those  last  alluded  to :  the  very 
slender  shape  of  its  apex,  however,  smooths  the  passage 
to  the  V.  hraziliana  of  Solander,  ■ —  remarkable  not  only 
for  its  pointed  spire,  and  its  ventricose  shape,  but  from 
possessing,  like  V.  anguhta,  only  three  plaits  to  the 
pillar.  It  is  clear  that  this,  as  well  as  C.  mitis,  are  aber- 
rant forms. 

(96.)  In  the  next  genus,  Harpula,  the  form  of  the 
apex,  which  is  the  main  character  of  Voluta,  became 
somewhat  variable  in  Cymhiola  ;  but  in  this  genus  it 
is  so  uncertain,  that  it  must  be  regarded  only  as  of  se- 
condary importance.  The  numerous  plaits,  which  ex- 
tend the  whole  length  of  the  pillar,  are  the  most  certain 
distinction  of  Harpula,  which  is  also  a  more  numerous 
genus  than  the  last.  Of  the  two  primary  types,  one  is 
seen  in  H.  vexillum,  which  is  smooth,  with  a  papil- 
lary spire  j  the  other,  seen  in  H.  hehrcea  (fig.  12.  b,  in 
p.  108.),  is  muricated,  with  the  tip  of  the  spire  obtuse,  re- 
gular, conical,  and  hardly  enlarged.  There  are,  however, 
other  shells,  obviously  belonging  to  this  group,  which 
will  not  arrange  with  either  of  these  two  divisions.    One, 


CHAP.   IV. 


HARPULA,  VOLUTILITHES,  SCAPHELLA. 


107 


the  Harpula  fulminata,  has  much  the  shape  of  a  Fascio- 
laria,  but  with  the  top  of  the  outer  lip  slightly  angulated 
and  dilated,  something  in  the  same  way  as  Valuta 
Scapha  and  Cym.  mitis.  The  enlarged,  knob-like  form 
of  its  apex  immediately  reminds  us  of  Voliita  papillaris ; 
while  in  its  markings,  and  in  the  thickness  of  the  outer 
lip,  internally,  it  perfectly  resembles  Scaph.  undidata. 
The  numerous  plaits,  however,  clearly  show  it  is  a  Har- 
pula. Another,  our  H.  lyriformis,  is  the  only  recent 
volute  whose  spire  is  longer  than  the  aperture ;  and  a 
third  aberrant  type,  the  H.  hullata,  stands  at  the  con- 
fines of  this  genus,  and  forms  a  passage  to  the  next. 

(97.)  VoLUTiLiTHEs,  SO  far  as  is  yet  known,  is  a 
genus  found  only  in  a  fossil  state ;  unless,  indeed,  Vo- 
luta  nucleus  Lam.,  peculiar  to  the  Australian  seas,  be 
considered  as  coming  within  its  limits :  it  exhibits 
none  of  the  delicate  plaits  on  the  pillar  of  Harpula  ;  so 
that  one  half  of  its  characters  belong  to  that  genus,  and 
the  other  half  to  this.  The  typical  characters  of  Volu- 
tilitlies  have  already  been  detailed  (92.)  ;  and  as  we  shall 
particularly  notice  the  subordinate  types  hereafter,  we 
may  pass  onward  to  the  next  group. 

{9^'^  The  last  of  the  primary  divisions  is  the  Aus- 
tralian genus  ScAPHELLA  ;  the  best  known  type  being 
the  Scaphella  undulata  {fig.  11.  a).  All  of  these  hitherto 
discovered,    are   natives   of  the    South   Pacific    Ocean. 


We  are  not  aware  that  any  of  these  shells  have  an  epi- 
dermis, and  their  uniform  smoothness  leads  us  to  con- 
clude they  are  partly  covered  by  the  dilated  lobes  of  the 


108 


SHELLS    AND    SHELL-FISH. 


PART   I. 


mantle,  as  in  the  Olhnn(P.  This,  in  fact,  is  the  only  genus 
which  is  neither  spinecl,  muricated,  nor  tuherculated. 
The  spire  (6)  is  conic  and  somewhat  short ;  the  whorls  of 
the  apex  are  scarcely  papillose  ;  while  the  inner  margin 
of  the  lip  is  considerably  thickened.  The  plaits  on  the 
pillar,  as  to  number,  are  by  no  means  constant,  even  in 
the  same  species  ;  in  general,  there  are  four,  but  the  last 
is  always  the  smallest.  Sometimes,  however,  the  pillar, 
at  this  part  of  the  aperture,  is  thickened,  and  there  are 
five  or  even  six  plaits  confused  and  irregular*,  as  in  S, 
papillaris  (Jig.  12.  «).   This  latter  type  is  remarkable  for 


its  apex,  which  is  suddenly  enlarged  into  a  thick  nipple- 
like form  (6),  similar  to  Harpula  falminata,  and  very 
much  like  the  published  figure  of  Voluta  fulgetrum. 
From  this,  it  is  clear  that  we  have  again  arrived,  almost 
unconsciously,  among  the  aberrant  forms  of  the  melon 
volutes  ;  ^or  fulgetrum  connects  papillaris  to  magnifica, 
which,  with  the  form  oi  fulgetrum,  assumes,  as  it  were, 
that  particularly  large  spire  which  is  the  chief  character 
of  the  genus  Foluta.  Scaphella  papillaris,  on  the  other 
hand,  is  closely  connected  to  our  S.  fusiformis,  which 
thus  unites  it  also  to  S.  nndulata. 

(99')  Here  we  close  our  remarks  on  the  affinities  of 
these  magnificent  shells  ;  but,  before  we  enter  upon  the 
consequences  of  this  distribution,  we  shall  endeavour  to 
meet   some   objections   which  may  possibly   be   raised 

*  This  deviation  is  not  uncommon  in  Scaphella  vndulafa  :  four  is  the 
usual  number  of  the  plaits  ;  but  sometimes,  as  Lamarck  observes,  there  are 
two  smaller  and  supernumerary  ones.  (Lam.  St/st.v'n.  i. 'i^").)  The  same 
variation  is  seen  in  Scaph.  Jttnonio. 


CHAP.  IV.       RT^MARKS  ON  VOLUTA  ANGULATA.  1  Oy 

against  it.  First,  it  may  be  urged,  that,  although  the 
series  between  the  smooth  melons  and  such  shells  as  Va- 
luta Scapha  is  sufficiently  obvious,  still,  that  the  Volutd 
angulata  can  never  follow  Scapha.  This  objection  seems 
well  grounded,  and  certainly  deserves  attention.  We 
admit  that  angulata  has  a  spire  totally  different  from 
that  structure  which  we  maintain  is  typical  of  the 
group,  wherein  we  have,  nevertheless,  placed  it.  But 
is  there  anything  extraordinary  in  this  arrangement  ? 
Does  there  exist,  in  any  one  class  of  the  animal  king- 
dom, a  natural  group,  wherein  all  the  species  exhibit 
the  whole  of  the  typical  characters  ?  Every  naturalist, 
every  systematist,  knows  full  well  that  no  such  group  is 
to  be  found.  It  has  been  well  said,  by  one  of  the 
most  distinguished  naturalists  that  this  country  has 
produced,  that  if  a  species  possesses  two  out  of  the  three 
characters  of  the  genus  in  which  it  is  placed,  this  is  all 
we  can  expect ;  and  the  reason  of  this  is  obvious :  if 
all  the  species  possessed  all  such  characters,  then  there 
would  be  no  gradation  of  structure  —  no  links  in  the 
chain  of  affinity — no  loss  of  one  structure — and  there- 
fore no  taking  up  that  of  another.  Now,  all  this  is 
diametrically  opposed  to  facts ;  for  the  whole  creation  is 
but  one  connected  chain  of  such  graduated  progressions, 
— unequal,  indeed,  yet  still  graduated.  The  affinity  of 
Scapha  to  angulata  is  not  so  intimate  and  direct  as 
many  others  in  the  series  ;  but  this  is  nothing  to  the 
purpose,  —  because,  as  we  have  just  said,  affinities  may, 
and  do,  vary  in  degree :  the  question  is,  whether,  be- 
tween these  two  shells,  there  is  a  sufficient  resemblance  to 
constitute  any  degree  of  affinity  ?  AFhen  we  compare 
the  angulated  apertures,  the  form  and  proportion  of  their 
plaits*,  and  the  thick  enamel  spread  over  their  spire, 
we  see  an  affinity  which  to  us  is  unquestionable.  If 
angulata,  in  short,  had  a  papillary  spire,  instead  of  a 
pointed  one,  it  would  be  of  the  same  type  or  sub-genus 
as  Scapha  !  the  pointed  spire,  therefore,  was  necessary 

*  Not  tlieir  number,  for  in  angulata  there  is  one  less. 


110  SHELLS    AND    SHELL-FISH.  FART   1. 

in  two  respects; — first,  to  show  that  this  shell  was  the 
prototype  of  the  genus  Volutilithes  ;  and,  secondly,  to  se- 
parate it  from  V.  Scapha.  The  next  type  we  place  after 
angulataisfulgetrum,  with  which,  also,  comes  magnifica. 
Now,  the  complete  glazing  of  angulata  (which  shows 
the  great  size  of  the  animal's  mantle)  is  partially  car- 
ried on  to  fulgetrum,  which  Mr.  Sowerby  thus  describes  : 
—  "  The  left  lobe  of  the  mantle  of  the  animal  must  have 
been  very  large,  since  the  columella  lip  is  extended  so  as 
to  cover  half  of  the  lower  volution."  And  that  this 
shell  exhibits  a  further  affinity  to  the  slender  spire  and 
angulated  body-whorl  of  angulata,  is  evident  on  the 
same  testimony.*  Evidence  of  this  sort,  from  an  un- 
prejudiced writer,  is  the  very  best  that  can  be  produced, 
since  it  is  given  without  any  idea  of  the  use  it  may  be 
applied  to. 

(100.)  Our  arrangement  of  the  Lamarckian  volutes, 
being  thus  founded  solely  upon  affinity,  would  seem  to 
require  no  additional  corroboration  ;  but  beneath  the  sur- 
face of  this  beautiful  chain  of  relationship,  lies  another, 
even  more  interesting,  which  can  be  only  brought  to 
light  by  comparing  the  analogies,  which  all  these  vari- 
ations in  form  present  among  themselves.  These  re- 
semblances are  so  remarkable,  that  we  shall  now  enter 
upon  them  very  fully.  To  do  this  in  all  cases,  even 
were  it  possible,  might  be  tedious  ;  but  in  the  present 
instance  it  is  almost  unavoidable,  inasmuch  as  we  desire 
that  our  theory  on  the  laws  of  representation  among  the 
Testacea  should  stand  or  fall  according  to  the  success 
or  failure  which  may  attend  their  exposition  in  this  and 
the  two  preceding  families. 

(101.)  The  principles  of  natural  classification,  so  fully 
explained  in  the  second  volume  of  this  series,  and  the 
innumerable  proofs  taken  from  every  class  of  vetebrated 
animals  that  have  been  brought  forward  in  the  succeed- 

*  y\  Julgetriim  "is  easily  distinguished  by  its  acuminated  papillose 
spire,  and  by  the  obtuse  angle  on  the  upper  part  of  the  last  volution.''  — 
Sow.,  in  Tankervillc  Cat.  p.  29. 


CHAP.   IV 


ANALOGIES    OF    THE    VOLUTIDiE. 


Ill 


ing  treatises,  are  so  well  known  to  the  majority  of  our 
readers,  that  it  would  be  superfluous  again  to  repeat  them. 
But  before  we  apply  this  theory  to  the  group  before  us, 
a  previous  question  must  be  first  disposed  of,  —  namely, 
upon  what  grounds  we  determine  that  the  melon  volutes 
are  the  pre-eminent  types  of  the  whole  family  ?  Now, 
we  do  not  regard  this  as  a  matter  of  speculative  opinion  ; 
it  must  be  determined,  in  fact,  by  the  analogies  which 
the  group  possesses,  as  a  whole,  to  other  groups.  The 
following  table  appears  to  us  to  decide  this  question : — 


Analogies  of  the  Zoophagous  and  Phytophagous 

Gasteropoda. 


Families  of  the 
Zoophaga. 

MURICID^. 
TURBINELLID^. 

VOLUTID^ 

Cyprsidje. 

STROiVIBID^. 


Analogical  Characters. 

Typical. 

Sub-typical. 

fFoot  of  the  animal   excessivelyl 
I  large  ;  tentacula  very  short ;  eyes  | 
<j  sessile  ;  shell  with  an   enormous  )- 
I  body-whorl,  and  a  short,  nearly  | 
(^obsolete  spire.  J 

f  Shell  smooth,  glossy,  partly  cover-  7 
X     ed  by  the  animal's  mantle.  3 

Animal  with  a  respiratory  siphon. 


Families  of  the 
Phytophaga. 

Helicid^. 
Trochid^. 


Haliotid*. 

Katicip.e. 
Turbid^. 


Now,  as  the  ear- shells  are  at  the  head  of  the  Halio- 
tidce,  it  consequently  follows  that  the  melons  have  the 
same  rank  among  the  Folufidce.  The  perfect  ana- 
logy of  the  two  families  is  equally  remarkable,  whether 
we  look  to  the  animals  or  to  their  shells  :  nay,  it  might 
be  carried  still  further  ;  for  as  there  are  coronated  and 
smooth  melon  volutes,  so  are  there  among  the  ear- 
shells,  —  one  division  of  the  latter  having  their  per- 
forations smooth,  the  other  having  them  elevated  or 
coronated. 

(102.)  We  may  now  at  once  compare  the  five  genera 
of  the  VolutincB  with  the  five  primary  divisions  of  th(^ 
whole  family. 


112 


SHELLS    AND    SHELL-FISH. 


PART  I. 


Analogies  of  the  Genera  of  the  Volutin.e  to  the  Volu- 

TID^. 


Genera  of  the 
Volutins. 

Valuta. 

Cymbiola. 

Harpula. 

Volutilithes . 
ScapheUa. 


Analogical  Characters. 

f Shell  ventricose,  smooth;    spire 7 
X     excessively  short.  j 

Shellmuricated;  spire  lengthened. 
C  The  whole   pillar  covered  with  7 
\     slender  plaits.  3 

f  Aperture  very  effuse ;  spire  acute ;  1 
t     base  of  the  pillar  alone  plaited.  J 


{ 


Spire  very  short ;  outer  lip  sinu- 


ated   or  detached  above, 
thickened  internally. 


and 


} 


Sub-families  of  the 

'    V0LUTID.ffi. 

Volutin*. 

Mitring. 

Olivine. 

ancellarin& 
Marginellinj;. 


So  completely  are  the  five  sub-families  of  the  Volu- 
tid(E  thus  represented  by  all  the  Lamarckian  volutes,  that 
the  analogical  characters,  or  those  common  to  both^ 
will  almost  serve  to  distinguish  each,  when  joined  to 
the  peculiar  one  which  separates  the  two  series.  It 
will  be  as  well,  however,  to  apprise  the  conchologist, 
that  the  real  type  of  the  MitrincB  is  our  genus  Ttara^ 
and  not  that  of  Mitra,  as  formerly  supposed. 

(103.)  Having  bestowed  no  ordinary  labour  in  our 
attempt  to  work  out  the  natural  affinities  of  the  Muri- 
cidce,  we  were  curious  to  ascertain  how  that  arrange- 
ment would  tally  with  the  present.  The  result  will 
be  seen  from  the  following  table: — 


Analogies  of  the  Volutid^  and  the  Muricid^. 


Sub-families  of  the 

VOLUTlNiE. 

Valuta. 


Cymbiola. 

Harpula. 

Volutilithes. 

ScapheUa. 


Analogical  Characters. 

("Shell  ventricose;  spire  remarkably  1 
X     short.  3 

f  Shell  muricated  with  spines  or  tu-  7 
(      bercles  ,  si)ire  more  lengthened,  j 

Spire  often  excessively  lengthened. 

C  Aperture  very  effuse  ;  base  of  the  7 
\     pillar  grooved  or  plaited.  J 

r  Outer  lobe  of  the  mantle  much  di-  y 
<  lated  ;  rc})resenting  Marginclla,  > 
C.     and  consequently  Nassa.  j 


Sub-families  of  the 

CASS1D£. 

Cassincs. 


Muricina:. 
Buccininit. 
Fwpuri7i(e. 

Nassiiitc. 


In  this  and  the  last  set  of  analogies,  we  again  have 


CHAP.  IV.  VOLUTA TYPES    OF    FORM.  113 

an  instance  of  that  inequality  in  analogical  relations, 
which,  in  our  former  volumes,  we  have  so  frequently  ad- 
verted to.  This  inequality,  strangely  enough,  has  been 
somewhere  urged  as  an  objection  to  the  theory  of  repre- 
sentation. Such  reasoners  seem  to  suppose  that,  unless 
all  groups  possess  the  same  degree  of  resemblance  to 
each  other,  the  evidence  is  inconclusive.  On  this  plan, 
an  eagle  and  a  lion  may  perhaps  be  admitted  as  analo- 
gotis ;  but  a  carnivorous  insect  and  a  carnivorous  beast 
cannot  be  so,  because  the  analogy  is  remote  or  obscure. 
But  if  there  are  any  analogical  resemblances  in  nature, 
it  follows,  as  a  necessary  consequence,  that  such  resem- 
blances are  strong  or  faint,  near  or  remote,  according 
to  the  proximity  or  distance,  the  similarity  or  the  dis- 
similarity, of  the  objects  compared.  Thus  it  is  in  the 
present  instance  :  the  groups  being  remote,  their  analo- 
gies are  not  strong  ;  nevertheless  they  are  substantially 
true,  —  because  they  are  perfectly  verified  through  the 
medium  of  other  or  intervening  groups,  which,  from  being 
more  alike,  render  the  analogies,  in  the  same  proportion, 
more  obvious  or  direct. 

(104.)  We  may  now  proceed  a  step  further,  and 
apply  the  same  description  of  proof  to  the  sub-genera, 
or  types  of  form,  of  the  typical  genus  Voluta,  upon  the 
affinities  of  which  we  have  already  said  so  much.  We 
leave  it  to  be  determined  by  others,  whether  these  types 
of  form  should  be  designated  as  simple  divisions,  or  as 
sub-genera,  and  therefore  to  be  distinguished  by  a  pa- 
tronymic name.  That  this  will  ultimately  be  done,  we 
have  no  doubt ;  because  they  are  of  the  same  rank  as 
the  sub-genera  of  the  other  families.  The  shells  which 
we  view  as  types  of  form  in  the  restricted  genus  Voluta, 
are  as  follows :  —  Voluta  Neptmii,  V.  imperialism  V. 
Scapha,  V.  angulata,  and  V.  magnifica.  We  shall  now 
place  these  in  one  column,  the  two  extremes  of  which, 
as  we  have  already  shown,  meet,  and  form  a  circle : 
the  next  column  is  composed  of  the  genera  of  the  La- 
marckian  volutes,  which  also  form  another  circle.  Now, 
if  the  contents  of  one  represent  the  contents  of  the  other, 

I 


114 


SHELLS    AND    SHELL-FISH. 


PART  1. 


without  any  variation  in  the  order  in  which  each  divi- 
sion respectively  stands  in  regard  to  affinity,  then  all 
the  verification  that  analogies  can  possibly  give,  will  have 
been  attained. 


Analogies  of  the  Sub- generic  Types  in  the  Genus 

VoLUTA. 


Typical  Species. 

/'.  Neptuni. 

V.  hnperialis. 

y.  Scapha. 
y.  angulata. 

V.  magnifica. 


] 


Analogical  Characters. 


fVentricose ;  egg-sliaped  ;  spire"? 
\     very  short,  or  none.  j 

Sub-ventricose ;  spire  more  pro- 
duced ;  the  body-whorl  and 
spire  coronated. 

f  Upper  angle  of  the  outer  lip  ad-  > 
i    vancing  up  the  first  spiral  whorl.  5 

("  Spire  with  the  apex  acute,  and  not  V 
I      papillary.  3 

r Columella  lip  thin  and  mucho 
■<  spread ;  shell  sub-fusiform ;  > 
t     spire  short.  3 


Genera  of  the 
J'ulutincc  Sw.  or 
VoLUTA  Lam. 

Valuta. 

Cymhiola. 

Harpula. 
Voltitilithes. 

Scaphella. 


Four  out  of  the  five  analogies  of  this  table  are  so  clear 
and  definite,  that  they  scarcely  require  further  illustra- 
tion. We  thus  see  how  imperialis  represents  the  bat 
volutes ;  angulata,  again,  puts  on  the  pointed  spire  of 
Volutilithes ;  while  magnifica  connects  Scaphella  with 
the  melons.  The  analogy  between  Scapha  and  Harpula 
(the  heavy  tuberculated  species  of  the  latter  being  the 
true  types),  although  less  apparent  on  a  cursory  view, 
is  still  very  remarkable.  The  strong  resemblance  which 
V.  Scapha  bears  to  a  Stromhus,  must,  indeed,  strike  the 
most  casual  observer  ;  but,  we  confess,  it  was  some  time 
before  we  discovered  the  singular  character  so  prevalent 
in  all  the  HarpulcB,  or  music  volutes,  where  the  outer 
lip  is  extended  up  the  first  spiral  whorl,  — a  structure  so 
universal  among  the  Strombidrp,  or  wing-shells,  and 
which  is  not  found  in  any  other  group  of  the  volutes. 
To  put  this  analogy,  however,  in  a  clearer  light,  we  shall 
now  compare  the  types  with  the  great  circle  of  the  Zoo- 
phaga. 


Genera 

Families 

of  the 

Analogies. 

of  the 

YOLVTINJE. 

Zuopfiaga. 

CHAP.   IV.  VOLUTA  TYPES    OF    FORJU.  115 

Analogies  of  the  Types  of  Voluta  to  the  Zoophagous 

Trihe. 

Types  of 
yoluia. 

T  •  1-       ^      J-  7         ("Spines  often  largeand  acute:  7  Af„„.  .^:^ 

Impenahs.    Cyynbwla.      \    ^pi^e muricated.  'JMuRiciDf. 

vi     .      .  ir  ■  .  f  Spire vervshort, smooth; apex  7 Ti..„„,„„,    .„_ 

Neptuni.        yoluta.  {    %iiiary  ;  plaits  distinct,     j  TuRBiNELLiDiE. 

Magnifica.    ScapheUa.         Mantle  very  large.  Volutid^. 

Angulata.     VolutiUthes.  { '^^^^^^^^^  '*'""  '°''^'^'^  ^'^*^  ]  Cvpr^id*. 

...  TT         >  f  Outer  lip  strongly  angulated  7  o...  _ 

Scapha.  Harpula.       J     or  elevated  on  the  spire.      j  Strombid^. 

This  table  brings  out  two  remarkable  facts.  —  The  first 
relates  to  the  analogies  of  Voliita  Scapha  and  of  Har- 
pula to  the  StromhidcB — all  which^  by  placing  these  three 
groups  in  separate  columns,  fall  in  precisely  opposite  to 
each  other.  The  second  relates  to  the  analogy  between 
the  Muricidcd  and  the  coronated  volutes :  these  are  all 
the  most  spiny  or  muricated  of  all  univalves.  The 
same  principle  of  variation  holds  good  between  the 
smooth  melons  and  the  typical  Turhinellidce  :  both  are 
remarkably  smooth  shells ;  both  have  very  short  papil- 
lary spires ;  and  both  have  three  or  four  well-defined 
plaits  on  their  pillar.  But  the  snh-typical  group  of  the 
TurbinellidcB  are  composed  of  those  rough,  spiny,  and 
often  coronated  shells,  forming  our  genus  Scolymus: 
these,  therefore,  are  analogous  to  the  sub-typical  genus 
Cymhiola  ;  and,  consequently,  to  all  such  forms  or  types 
as  represent  them,  as  Voluta  imperialism  Harpula  hehrcea, 
VolutiUthes  musicalis,  &c.  It  seems  to  be  one  of  the 
laws  of  variation  in  the  structure  of  the  zoophagous 
shells,  that  every  one  of  the  families  *  should  contain 
two  prominent  groups ;  one  remarkable  for  having 
smooth,  and  the  other  rough,  or  spiny,  shells.  It 
would  even  seem  that  Nature,  so  to  speak,  is  so  tena- 
cious of  this  law,  that  she  adheres  to  it  in  the  very 
smallest  of  her  groups,  —  that  is,  in  the  variations  of  sub- 
genera.    Among  the  most  common  instances,  the  reader 

*  Except  the  CyprccidiB,  where  it  is  obvious,  from  the  little  variation  in 
the  shells,  that  the  analogies  must  be  traced  from  the  animitls  cnly. 

I  2 


Il6  SHELLS    AND    SHELL-FISH.  PART  I. 

will  call  to  mind  the  smooth  and  the  coronated  helmets 
(Cassidea  and  Dolium),  the  smooth  TurhinellcE,  and 
the  murex-like  ScolymincB,  the  tuberculated  Stromhi, 
and  the  smooth  Cones.  The  same  principle,  again,  is  often 
carried  into  the  variation  of  each :  thus,  although  the 
Cones,  as  a  whole,  are  smooth  shells,  yet  one  division  has 
coronated  tubercles.  Some  of  the  melon  volutes  are 
smooth,  as  V.  Neptuni;  while  others  (which  are  sub- 
typical)  are  coronated.  Every  division,  in  short,  large 
or  small,  in  the  entire  family  of  volutes,  exhibits  these 
differences.  The  reader  will  of  course  understand  we 
are  now  speaking  only  of  the  typical  and  the  sub-typical 
types ;  the  variation  of  the  aberrant  forms  being  regu- 
lated by  other  circumstances,  which,  in  the  present  state 
of  our  inquiries,  it  would  be  premature  to  venture  upon. 
(105.)  If  the  foregoing  arrangement  of  the  sub-ge- 
neric types  of  Voluta  be  really  natural,  it  follows  that  all 
the  melon  volutes  form  but  one  sub-genus.  Break  them 
up  into  other  sub-genera,  and  give  to  each  the  same 
rank  as  attaches  to  the  four  other  types,  and  the  whole 
harmony  and  beauty  of  the  theory  w^ould  obviously  be  de- 
stroyed ;  their  arrangement  would  then,  in  fact,  become 
an  arbitrary  matter  of  nomenclature.  Had  our  obj  ect  been 
to  have  formed  an  artificial  classification  of  the  Testacea, 
we  should,  without  hesitation,  have  adopted  the  views 
of  others  on  this  subject.  The  divisions  of  the  smooth 
and  the  coronated  melons  are  excellent,  because  they  are 
natural :  but  all  we  have  now  stated  shows  that  they 
are  two  sections  only  of  a  sub-genus.  It  will  be  evi- 
dent to  those  zoologists  who  may  be  conversant  wnth 
the  vertebrated  animals,  that  all  groups  pre-eminently 
typical  contain  a  greater  number  of  forms  than  any  other, 
as  if  Nature  intended  to  show  us,  at  the  onset,  the  rudi- 
ments of  all  those  variations  which  were  to  characterise 
the  surrounding  groups.  Lawrence,  long  ago,  observed 
of  the  Caucasian  race  of  man,  —  the  most  pre-eminently 
typical,  —  that  it  contained  more  numerous  variations 
than  any  other ;  and  we  have  shown  how  strictly 
applicable  this    assertion     to  the  vertebrated  animals. 


CHAP.   IV.       RANK    OF    THE    MELON    VOLUTES.  117 

Now,  the  melon-shells,  forming  our  genus  Voluta,  are  of 
this  description  ;  they  stand  at  the  head  of  the  whole 
family  ;  and  we  accordingly  fmd  their  subordinate  types 
are  not  only  the  most  varied,  but  the  most  numerous. 
Vol.  imperialism  Scapha,  anguhita,  and  magnifica  enter, 
indeed,  into  their  circle;  but  they  do  not  form  the  highest 
point  of  perfection.  This  is  seen  only  in  the  melons, 
strictly  so  termed ;  yet,  even  here,  how  great  is  the 
diversity  of  forms  !  We  have  some  with  a  spire  alto- 
gether hid,  and  the  shell  devoid  of  colour,  as  in  Nep- 
tiini;  others  with  the  indication  only  of  a  mis-shaped 
spire,  as  in  V.  Cymhium,  yet  with  marbled  variegations  : 
another  little  assemblage  has  coronated  and  vaulted 
spines ;  and  even  among  these,  the  spire  is  so  varied, 
that  in  one,  V.  tessellata,  they  are  compressed,  as  it  were, 
over  an  extremely  short  spire,  which  they  almost  hide  ; 
or,  as  in  diadema,  they  are  long,  and  directed  forwards : 
finally,  there  is  one  (F".  Broderipia)  which  deviates  so 
much  in  its  general  shape  and  habits  from  all  others, 
that  it  will  not  strictly  arrange  with  these  coronated 
melons,  or  with  the  next  type,  F.  imperialis.  Now,  all 
these  variations  absolutely  occur  in  the  compass  of  a 
single  sub-genus :  and  we  may  explain  this  diversity  by 
supposing  that  the  coronated  melons  typify  the  genus 
Cymhiola  and  V.  imperialis;  that  the  smooth  melons 
are  the  true  representatives  of  the  whole ;  and  that  the 
V.  Broderipia  is  an  aberrant  form  connecting  the  coro- 
nated melons  with  Voluta  imperialis.  That  such  shells 
as  Voluta  JEthiopica  are  much  more  perfect  (abstractedly) 
in  structure  than  Neptuyii  and  its  allies,  is  unquestion- 
able :  but  this  does  not  imply  typical  perfection  ;  for  it 
frequently  happens  in  aberrant  groups  (as  the  Volutidct 
is  among  the  Zoophaga),  that  the  typical  character  rests 
on  very  different  considerations. 

(1 06.)  It  will  be  needless  to  go  into  all  the  details  of 
the  next  genus,  Cymhiola.  Yet  it  will  be  satisfactory 
to  see  how  intimately  the  types  represent  those  of  the 
Voluta, — at  least,  in  their  main  characteristics.  In  the 
following  table,  therefore,  we  have  selected  those  species 

I  3 


118  SHELLS    AND    SHELL-FISH.  PART  I. 

which  have  been  already  alluded  to  ;  premising  only 
that  some  doubts  hang  over  the  true  nature  of  the  type 
which  intervenes  between  the  bat  volutes  (C.  vespertilio) 
and  C.  tuherculata,  chiefly  arising  from  our  not  having 
these  shells  immediately  before  us.  This  point,  there- 
fore,, must  for  the  present  be  left  open  to  doubt.* 

Analogies  of  Voluta  and  Cy3Ibiola  with  the  Genera. 

„       .        ~  c       ■        c  Genera 

^^'':Zf  Analogies.  l^Zl?.l  .of  the 


Voluta.  ^nu^u^cc,.  Cymbiola. 


VOLUTINiE. 


»T    s     ■         f  Body-whorl  ventricose :  shell  7  4,    /;„  -ir-^,.,^. 

Neptum.        i     sijJooth  c  Anctlla.  Voluta. 

r  ■  ,■      C  Shell  not  ventricose  ;  whorls  7  7' „  ^„ ,,■/•„        n,,,,,,,^.  . 

Impermhs.   J     coronated  and  spined.  \l  espe^tUio.       Cymbiola. 

Scapha.  Smooth  ;  outer  lip  angulated.    Mitis.  Harpula. 

Angulata.         Aperture  effuse;  spire  pointed.    Braziliensis.    Volutilithes- 
Magnifica.     [  '^"^'."Jfil^^'";"'"^ '  ^P^^^^^^^oth,  j  y,,^„.,„^„,„.    Scaphella. 

Cymbiola  tuherculata  t^  from  having  a  greater  number 
of  plaits  than  any  other  of  its  genus,  seems  to  connect 
Cymbiola  with  Harpula,  through  the  medium  of  H.  ful- 
getrum;  and  at  the  same  time  to  pass  into  Cymbiola 
Braziliensis  % ;  which  last,  by  its  effuse  aperture,  the  acu- 
minated apex  of  its  spire,  and  its  possessing  only  three 
plaits,  is  a  perfect  representation  of  Voluta  angulata. 

(107.)  The  genus  Harpula  commences  with  the 
Harpula  fulminata§,  one  of  the  most  interesting  forms 
in  the  whole  family.  Its  shape  is  that  of  a  Fasciolaria, 
the  base  being  produced;  while  the  apex  is  so  papillary 
that  it  forms  a  large  knob,  almost  completely  round :  it 
is,  in  fact,  the  first,  or  terminal,  whorl  which  is  thus 
inflated ;  and  the  little  turn  which  this  whorl  makes  is 
not  on  the  top,  but  on  the  side.  Now,  this  formation  is 
only  seen  in  Scaphella  papillosa,  but  it  is  indicated  in 

*  A  full  investigation  of  the  animals  of  the  Pacific  volutes  will  claim 
our  first  attention,  after  the  settlement  we  intend  making  on  the  romantic 
and  ])rolific  shores  of  New  Zealand. 

f  Exotic  Conch. 

t  Chemnitz,  pi.  176.  figs.  1695, 1696.  The  Vo/ufa  rud's,  of  which  a  figure 
has  been  published  in  Gr{ff'.  Ci/v.  pi.  SO.  fig.  1.,  seems  to  me  a  typical  melon 
volute  ;  but  nothing  further  is  said  about  it,  than  that  it  is  "  clay-coloured 
mixed  with  white." 

^  Ency.  Meth.  pi.  381.  fig.  2. 


CHAP.    IV.  TYPES    OP    HARPULA.  ]  19 

H.  hullata,  and  a  very  near  approach  to  it  may  be 
traced  in  Harpula  vejcillum.  We  thus  have  three 
resemblances ;  one  of  which  only  we  shall  at  present 
regard.  The  numerous  plaits  of  fiilminata  evince  its 
proximity  to  vexillum  and  Lapponica.  To  these  succeed 
the  pre-eminently  typical  forms  composed  of  Harpula 
hehrcEa,  musica,  polyzonalis,  sulcata,  Sec,  all  of  which 
are  thick,  muricated,  or  spined.  By  these  a  passage  is 
formed  to  those  slender-ribbed  species  where  the  two 
last  plaits  are  decidedly  the  thickest,  and  the  upper  ones 
either  very  slender,  as  in  Harpula  lyriformis"^;  or  nearly 
obsolete,  as  m  Harpula  costataf ;  or  perfectly  wanting,  as 
in  Harpula  nucleus.^  In  the  apex  of  these  shells^  how- 
ever, here  is  a  marked  difference,  plainly  indicating  a 
gradation  of  structure :  thus,  in  costata  and  multi- 
costata  §,  the  apex,  although  obtuse,  is  not  swelled,  and 
the  volutions  appear  to  be  graduated  equally,  as  in  Har- 
pula polyzonata.  In  nucleus,  the  apex  seems  almost 
acute  II  ;  but  in  H.  lyriformis  the  second  volution  is 
swelled  and  papillary :  it  is  by  this  shell,  therefore, 
that  we  may  pass  to  the  next  type  of  form,  represented 
by  our  Harpula  hullata^,  where  the  shell  retains  the 
same  shape  as  H.  nucleus,  and,  like  that,  has  only  two 
distinct  plaits ;  the  whole  shell  is  quite  smooth ; 
the  spire  is  not  only  very  obtuse,  but  the  terminal  volu- 
tion is  enlarged,  even  in  the  worn  individual,  which  is  the 
only  one  we  have  yet  seen;  and  its  last  turn  is  placed 
on  the  side,  not  at  the  apex.  For  this  form,  however, 
we  have  been  prepared  by  the  Harpula  lyrifornns,  so 
that  we  return  again  to  the  singular-shaped  spine  of 
Harpula  fulminata.     Between  H.  hullata  and  H.  ful- 

*  Zool.  Journ.  iii.  pi.  3.  Zool.  Illust,  first  series,  pi.  54. 

t  Brand's  Journal,  xvii.  p.  33. 

X  Mawe's  Conchology,  frontisp.  fig.  2. 

\  Broderip,  in  Zool.  Journ.  iii.  pi.  3.  fig.  2. 

II  I  am  not  positive  on  this,  not  having  a  perfect  example  at  this  time 
before  me. 

IF  The  only  specimen  I  have  yet  seen  of  this  shell  is  figured  in  Zool.  III. 
2d  series,  pi.  15. ;  nor  am  I  aware  of  any  other,  at  least  in  the  London  cabi- 
nets. Papillary  spires  are  always  remarkably  thick  ;  and  as  it  was  evident 
this  specimen  had  been  beaten  and  battered  on  the  sea  beach,  it  is  highly 
probable  that  the  apex  was  originally  much  more  thick  and  inflated  than  it 
was  on  coming  to  my  hands.     It  is  now  in  the  British  Museum. 

I  4 


120  SHELLS    AND    SHELL-FISH.  PART   I. 

minata  we  are  disposed  to  place  a  most  singular  volute, 
described  with  Mr.  Broderip's  usual  accuracy,  which 
partakes  both  of  one  and  the  other.  It  has,  in  fact, 
almost  precisely  the  same  elongated  shape  as  a  young 
specimen  of  fulminata,  before  the  outer  lip  has  been 
formed;  while  the  number  of  its  plaits  are  only  two,  thus 
agreeing  with  bidlata.  Divest  the  fulminata*  of  its  outer 
lip,  and  it  would  have  the  same  "  fig-like"  appearance 
as  Mr.  Broderip's  R.  duhia.\  That  the  plaits  on  the 
pillar  of  some  of  these  shells  increase  with  age,  is  proved 
by  a  young  Ho  vexillum,  now  before  us,  which  has  only 
four,  instead  of  eight. 

(108.)  In  this  manner,  as  it  appears,  the  genus 
Harpula  forms  a  circular  group,  which,  by  commencing 
with  H.  fulminata,  passes  onward  to  Lapponica  and  vex- 
illum, and  from  thence  to  hebrtea  :  polyzonata  conducts 
us  to  costata  ;  and  lyriformis  to  nucleus  and  hullata  ; 
while  dubia  brings  us  again  to  fulminata.  We  may 
now  compare  the  contents  of  this  circle  with  the  last. 

Analogies  of  the  Genus  Harpula. 

Sub-generic  Genera         Sub-generic 

Types  of  Analogies.  of  the  Types  of 

Harpula.  Volutins.        Voldta. 

H.fulminata.    Lower  plaits  ofthe  pillar  small.  Scaphella.        Magtiifica. 
vexillum.       Shells  smooth.  Voluta.  Neptuni. 

f  Shells  niuricated  or  nodulous;  ^ 
heb7-cea.       ^     apex  obtuse,  but  not  much  vCymbiola.         Imperialis. 

L     enlarged.  3 

„.   ,  CPlaits   numerous,  the  lowers  ii.o„.,. .  Q^^^h^ 

costata.       ■{     1         1  -1,1  t  Harpula.  bcapna. 

I     largest ;  apex  variable.         i  ^ 

bnllata.         Plaits  on  the  pillar  very  few.     Volutilithes.  Angvlata. 

*  I  have  recently  come  to  a  knowledge  of  the  habitat  of  this  shell,  which 
is  Java. 

f  As  Mr.  Broderip's  observations  on  this  shell  will  be  much  more  valu- 
able than  my  own,  the  reader  will  be  better  pleased  by  perusing  that  acute 
naturalist's  own  words.  "  This  shell  is  one  of  those  forms  which  convince 
us  ofthe  vanity  of  our  artificial  distinctions.  When  viewed  from  above,  it 
seems  as  if  the  spire  of  a  Voluta  were  placed  on  the  body-whorl  of  one  of 
those  Pyrnlce  which  are  commonly  known  by  the  name  of  Figs.  Turn  it, 
and  the  difficulty  of  classing  the  shell  is  rather  increased  ;  for  the  aperture 
is  still  fig-like,  and  it  requires  an  accurate  examination  to  detect  the  two 
almost  imperceptible  plaits  on  the  columella.  Tiie  apex,  indeed,  uncouth 
as  it  is,  shows  more  like  that  of  a  J'oluta  than  of  any  other  sliell,  and  it  is 
utterly  different  from  that  of  a  Pyrula.  Place  it  among  the  volutes,  and 
it  will  be  found  to  approach  nearest  to  V.  rupestris;  though  one  cannot  but 
suspect  that  there  are  yet,  in  the  bosom  of  the  deep,  many  gradations  of 
form  between  them.  There  is,  I  believe,  one  specimen  in  the  cabinet  of 
prince  Massina." — Brod.,  in  Zool.  Journ.  iii.  p.  81.  pi.  3.  lig    1. 


CHAP.   IV.        VOLUTILITHES  TYPES    OF    FORM.  121 

Of  the  resemblance  between  the  three  firsts  or  ful- 
minata,  Scaphella,  and  magnifica,  we  shall  have  to 
speak  hereafter.  The  group  which  contains  Harpula 
veocillum  and  Lapponica,  as  clearly  represent  the  smooth 
melons_,  as  hehrcea  does  the  bat  volutes  {Cymhiola). 
There  is  a  circumstance^  also^  regarding  H.  vejcillum 
and  Lapponica,  apparently  trivial,  but  of  peculiar  in- 
terest to  those  who  delight  in  analogical  researches : 
they  are  the  types  of  the  genus  Harpula,  which,  as  a 
whole,  we  have  shown  to  correspond  with  the  Stro7nbidce  ; 
and,  in  proof  of  this,  we  remarked  that  the  major  part 
presented  the  analogous  character  of  the  outer  lip  being 
carried  upwards  towards  the  spire.  But  this  is  not  the 
only  analogy :  at  the  base  of  the  outer  lip,  in  fine  and 
uninjured  specimens  of  vexillum  and  Lapponica,  is  a 
slight  but  very  distinct  sinus*,  rudimentary,  as  it  were, 
of  the  distinct  lobe  in  the  genuine  Strombi :  this  is  not 
seen  in  the  next  division,  represented  by  H.  hehrcea  ; 
but  then,  again,  these  latter  shells  have  the  top  of  the 
outer  lip  much  more  advanced  on  the  spire.  Costata 
not  only  represents,  but  is  actually  one  of,  the  HarpulcB  ; 
while  Folutilithes,  with  its  few  plaits,  is  equally  repre- 
sented by  hullata  or  nucleus. 

(109.)  The  types  of  form  in  Volutilithes  will  now 
be  inquired  into.  Throughout  all  the  species  we  have 
seen,  or  which  have  been  figured,  the  typical  structure, 
in  regard  to  the  paucity  of  plaits  and  the  acuteness  of 
the  spire,  seems  almost  universal.  The  first  group  which 
unites  these  sharp-pointed  volutes  with  //.  lyriformis, 
seems  to  be  such  shells  as  V.  costariaf,  which,  by  a 
series  of  other  species  furnished  with  distinct  convex 
ribs,  like  those  of  H.  lyriformis,  lead  us,  by  means  of 
muricina\,  to  musicalis  and  spinosa  §  (Jig.  12.  c,  in 
p.  123.)  :  a  third  type  is  represented  by  the  crenulata  and 
hicorona  \\   Lam. ;  a  fourth  by  his  rarispina  ;  and   the 

*  This  is  precisely  analogous  to  the  corresponding  prototypes,  Rhinedo- 
mus  and  Cyllene. 
t  Ency.  Meth.  pi.  383.  fig.  9. 
X  Ibid.  pi.  383.  fig.  1.  a,  and  pi.  381  fig.  3. 
§  Ibid.  pi.  392.  figs.  4,  5.  (|  Ibid.  pi.  384.  figs.  5,  6. 


122 


SHELLS    AND    SHELL-FISH. 


PART   I. 


fifth,  which  so  singularly  represents  Voluta  angulata 
and  Cymhiola  Braziliensis  (no  less  than  the  Fyrulce),  is 
seen  in  F.cithera*,  this  latter  being  the  second  type  of 
the  genus. 

(110.)  That  there  exists  mutual  resemblances  be- 
tween these  presumed  types^  and  those  of  the  three 
preceding  genera,  will  be  evident  from  the  following 
comparison  :  — 


Analogies  of  the  Genus  Volutilithes. 


Sub-generic 

Types  of 
Volutilithes. 


Analogical  Charactejs. 


Spinosa.-f 
Crenulata. 

Costaria. 

Cithera. 

Ra7-ispina. 


f  Shell     partially     or     wholly  7 
/      smooth.  J  J 

Shell  entirely  muricated. 
Spire       much      lengthened; ") 
outer  lip  well  developed 
apex    sometimes     slightly 
enlarged.^ 

Ventricose  ;  spire  very  short, 

'  Analogous  to  the Stromhidie; 
outer  lip  sinuated  at  the 
base,  and  often  detached 
above. 


Types  of 
Harpula. 

Genera  of  the 
Voluti.NjE. 

Vexillum. 

Voluta. 

Hebrcea. 

Cymbium. 

Lyrifonnis. 

Harplla. 

Bui  lata. 

Volutilithes 

Fuhm'naia. 

SCAPHELLA. 

Perhaps  it  may  eventually  turn  out  that  the  V.  musi- 
calis  II  —  a  species  we  do  not  possess  in  perfection  —  is 
one  of  the  typical  forms,  and  that  spinosa  is  the  other  : 
but  the  very  singular-grooved  suture  of  costaria  and 
bicorona  appears  to  indicate  that  a  peculiarity  of  structure 
existed  in  the  animal,  of  more  importance  than  the  mere 
form  of  the  shell.  The  analogy,  or  rather  the  affinity, 
between  costaria  and  the  HarpulcB  must  be  apparent  to 
every  one,  no  less  than  that  between  Voluta  angulata, 
Cymbiola    Braziliensis,    and    Volutilithes    cithera.     Of 

*  Ency.  Meth.  pi.  384.  fig.  1. 

f  It  is  not  a  little  remarkable,  that,  in  well-preserved  specimens  of  the 
fossil  species  from  France,  the  body-whorl  is  marked  by  transverse  orange 
lines,  completely  analogous  to  H.  vexillum. 

I  If,  as  may  be  suspected,  the  Voluta  labrella  (Ency.  Meth.  pi.  384.  fig.  3.) 
is  the  true  type  of  this  division,  then  its  analogy  to  the  smooth  melons 
would  be  perfect,  inasmuch  as  this  fossil  is  entirely  without  the  muricated 
spines  of  spinosa  :  1  do  not,  however,  feel  at  all  satisfied  that  I  have  cor- 
rectly indicated  this  and  the  next  type. 

(j  As  in  the  two  species  here  compared. 

II  Ency.  M^th.  pi.  392.  fig  4. 


CHAP.   IV. 


SCAPHELLA 


TYPES    OF    FORM. 


123 


V.  rarispina  we  can  only  form  our  conclusions  from 
the  figure  in  Ency.  Mtth.  384.  fig.  2.  It  would  seem 
from  this,  that  there  is  a  very  distinct  sinus  at  the  base 
of  the  outer  lip,  while  the  wide-spread  deposition  of 
enamel  on  the  inner  lip  reminds  us  both  of  the  genus 
Marginella  and  of  Voluta  Scapha  :  it  is,  in  short_,  the 
strombiform  type. 

(111.)  We  now  come  to  the  last  genus,  Scaphella. 
Although  these  shells  are  readily  distinguished  by  the 
experienced  malacologist  at  the  first  glance,  it  is  not  so 
easy  to  define  them  by  words.  Their  true  characters, 
we  apprehend,  will  be  found  in  the  animal.  They 
differ  from  all  other  known  volutes,  by  being  always 
without  sculpture,  and  generally  polished  like  the  Mar- 
ginellce.  The  apex  of  the  spire  varies  precisely  in  the 
same  way  as  in  the  genus  Harpula  :  in  the  chief  type, 
represented  by  S.  undulata,  it  is  small,  and  obtusely 
pointed.  In  fusiformis,  it  is  decidedly  thick ;  and 
in  papulosa,  it  becomes  exceedingly  large  and  round. 
A  shelly  deposition  is  often  formed  in  mature  age,  at 
that  part  of  the  outer  lip  which  joins  the  spire,  and 
also  on  the  pillar  side  of  the  aperture  :  there  is  a  con- 
stant propensity,  in  short,  to  this  thickening  of  the 
pillar,  even  in  shells  which  usually  have  their  plaits 
distinct.  The  first  advance  to  this  structure,  after 
leaving  the  last  genus,  is  by  a  very  singular  fossil  shell, 
described   by  Lamarck   as  the  Buccinum  strombio'ides. 


11 


(  fig.  12.  a,  b.)  Mr.  G.  B.  Sowerby,  in  adopting  this  name, 
justly  observes,  that,  but  for  the  absence  of  folds  on  the 


124  SHELLS    AND    SHELL-FISH.  PART  I. 

pillar,  its  characters  are  more  like  those  of  a  volute  than 
a  Stromhus.  One  circumstance,  however,  not  noticed  by 
either  of  these  writers,  must  be  here  mentioned  :  the 
whole  shell  is  covered  with  a  thin  coat  of  shining  enamel, 
as  in  some  of  the  recent  Scaphellce,  particularly  thick 
at  the  top  of  the  outer  lip.  This  is  always  apparent ; 
while,  in  old  ones,  there  is  also  a  thick  deposition  on 
the  upper  part  of  the  inner  lip,  which  spreads  over  all 
the  under  side  of  the  body- whorl.  This,  in  fact,  is  but 
a  slighter  developement  of  that  greater  thickening  of 
enamel  seen  in  the  last  shell  we  spoke  of, — namely,  the 
Volutilithes  rarispina ;  and  is  precisely  what  might 
be  expected  in  any  type  which  was  to  connect  it  with 
the  genus  Scaphella,  The  absence  of  plaits  on  the 
pillar  of  this  interesting  shell  (which  for  the  present  we 
shall  call  Scaphella  strombo'ides)  will  not  be  at  all  incon- 
gruous, —  because,  in  the  whole  of  the  Volutilithes,  these 
appendages  are  small,  and  frequently  almost  evanescent ; 
while  the  detachment  of  the  upper  part  of  the  outer 
lip  from  the  spire  plainly  shows  it  is  the  strombiform 
type  of  this  genus,  as  F.  rarispina  is  of  the  last. 

(112.)  Scaphella  being  thus  connected  to  Volutilithes, 
we  may  pass  over  the  two  chief  types,  represented  by 
S.  undulata  and  fusiformis,  and  recall  the  reader's 
attention  to  the  next  in  the  series,  —  namely,  Scaphella 
papulosa,  formerly  alluded  to.  Now,  there  are  two 
other  shells  which  more  especially  possess  this  kind  of 
nipple-like  apex,  and  in  the  same  high  developement, — 
the  Harpula  fulminata,  and  the  Voluta  fulgetrum  :  the 
question,  therefore,  is,  to  which  of  these  is  it  mostly 
allied?  On  this  point  we  reply, — to  the  latter  by  affinity, 
and  to  the  former  by  analogy.  It  thus  follows  that  we 
have  traced  the  series  of  the  volutes  once  more  up  to 
the  typical  genus,  which  we  enter  again  by  means  of 
Voluta  fulgetrum  and  magnifica. 

(113.)  The  four  types  of  Scaphella,  which  are  all 
we  at  present  know,  will  thus  find  their  respective  ana- 
logies. 


CHAP.   IV. 


SCAPHELLA TYPES    OF    FORM. 


125 


Types  of 

SCAPHELLA. 

Undulata. 
Fus'formis. 
Papulosa. 
? 

Strombdides. 


Analogies  of  the  Genus  Scaphella. 


Analogical  Characters. 

("Shell   very    smooth;    suture  > 
\      enamelled  ;  spire  small.       5 
Sub-ventricose ;  spire  thick. 

("Tip  of  the   spire  thick  and 7 
\     mammillary.  J 

? 
Inner  lip  thickened  and  gib- 
near  the  spire 
igular  and  prom 


!  Inner  lip  thickened  and  gib-"^ 
hoiis  near  the  spire  ;  outer  f 
lip  angular  and  prominent  T 
al  ove.  J 


Types  of 

/OLUIILITHES. 

Types  of 

VoLUTA. 

Crenidata. 

Cymbiola. 

Labrella  ? 

Neptuni. 

Costaria. 

Magnifica, 

Cithara. 

Angulata. 

Rarispina. 

Scapha. 

(114.)  This  is  the  proper  place  for  remarking  a  pe- 
culiarity in  Volutilithes  costaria,  which  we  have  not  ob- 
served in  its  allies;  the  apex,  although  pointed,  has  one 
of  the  volutions  thickened, —  so  that,  in  its  own  circle, 
it  becomes  exactly  what  papillosa  is  among  the  Sca- 
phellce. 

(115.)  The  peculiarly  strong  resemblance,  however, 
between  Scaphella  papillosa  and  Harpula  fulminata,  is 
too  remarkable  to  be  termed  a  simple  analogy.  This 
brings  us  to  another  peculiarity  of  the  natural  system,  of 
which  full  explanations  and  numerous  proofs  have  been 
adduced  in  our  former  volumes.*  The  study  of  the 
different  classes  of  the  vertebrated  animals,  however,  is 
quite  out  of  the  province  of  the  malacologist,  and  we 
cannot  suppose  that  he  will  assent  to  so  novel  a  theory, 
unless  it  be  proved  in  his  own  particular  walk.  We 
therefore  lay  before  him,  as  a  case  in  point,  the  aberrant 
groups  of  the  Volutince, — wa.m.e\y ,  Harpula,  Volutilithes, 
and  Scaphella.  The  series  in  which  we  have  placed 
these,  commences  with  Harpula  fulminata,  and  termi- 
nates with  Scaphella  papillosa.  Is  there  not  sufficient 
evidence  that  these  two  extremes  meet  ?  and  that  Sca- 
phella papillosa  is  as  nearly  related  to  H.  fulminata  as 
to  Voluta  fulgens  ?  If  so,  our  series  forms  a  circle. 
Thus,  we  find  the  whole  family  —  as  we  began  with 
assuming  —  constitutes   one   circular  group,   primarily 

*  Geography  and  Classification  of  Animals,  p.  226, 


126  SHELLS    AND    SHELL-FISH.  PARI    I. 

divided  into  three  other  circles,  —  the  first  of  which, 
Valuta,  is  typical ;  the  second,  Cymbiola,  is  sub-typical  ; 
and  the  third,  which  contains  Harpula,  Folutilithes,  and 
Scaphella,  constitutes  the  aberrant  circle.  This,  in  fact, 
is  only  in  conformity  with  all  other  natural  groups  in 
the  Vertebrata  ;  so  that,  if  the  principles  upon  which 
we  have  now  arranged  the  VolutincB  are  radically  de- 
fective, so  also  are  those  in  the  innumerable  groups 
that  have  been  thus  tested  and  verified  in  ornithology, 
ichthyology,  &c.  :  for  it  is  logically  certain,  that  unity  of 
plan  cannot  exist  in  the  animal  world,  if  one  and  the 
same  principle  of  variation  is  not  fundamental,  and  does 
not  pervade  all  its  parts, 

(1X6.)  The  Mitring,  or  mitres,  no  less  than  the 
volutes,  are  characterised,  in  the  great  majority  of  the 
species,  by  very  distinct  and  tangible  characters ;  but 
so  soon  as  we  reach  the  extreme  limits  of  each,  and 
look  for  those  marks  by  which  we  have  been  accustomed 
to  separate,  with  ease,  the  two  groups,  we  find  some 
of  them  gradually  disappear,  and  others  so  modified 
and  interchanged  as  to  render  it  very  difficult  for  an 
ordinary  naturalist  to  draw  any  positive  line  of  demarc- 
ation, —  at  least,  on  those  principles  of  absolute  division 
insisted  upon  by  some  writers.  It  has,  for  instance, 
been  thought  that  a  shell  having  the  spire  papillary, 
and  the  lower  plaits  upon  the  pillar  largest,  was  un- 
questionably a  volute:  and  yet  we  have,  in  Folutilithes, 
a  whole  assemblage  of  shells  whose  apex  is  acute  ;  and 
in  another  group,  Scaphella,  the  lower  plait  is  always 
the  smallest.  Among  the  mitres,  on  the  other  hand, 
we  shall  find  more  than  one  with  a  papillary  spire,  and 
others  where  the  lower  plaits  are  as  large  as  the  upper. 
Hence  it  follows,  that  if  no  groups  are  to  receive  ge- 
neric or  family  names,  but  such  as  are  distinctly  sepa- 
rated, and  are  destitute  of  these  intervening  links,  the 
old  genera  of  Valuta  and  Mitra  must  again  be  united. 
Nor  should  we  stop  here :  Mitrella  so  connects  the 
mitres  with  the  olives,  that  those,  too,  must  be  ab- 
sorbed in  this  gathering  conchological  snowball ;   and 


CHAF.    IV.  THE    MITRiiS    GENERALLY.  127 

with  OHva  must   follow  Ancillaria  :    in   this  way  we 
might  go  on  until  we  have  but  one  genus,  Voluta,    It  is 
only  by  thus  following  out  such  a  theory  of  nomencla- 
ture, that  we  see  the  full  results  to  which  it  must,  of 
necessity,   lead.     We  have,  indeed,  already  spoken  on 
this  subject ;  but  we  think  it  desirable  to  place  it  more 
especially  before  our  readers  in  this  place,   where  the 
opposite  plan  has  been  so  prominently  brought  forward. 
(117.)   The  whole  of  the  Mitring,  or  Lamarckian 
mitres,  were   considered   but  as  one  genus  until  about 
twenty   years   ago,  when  we  ventured  to  detach  from 
them  a  small  group  by  the  name  of  Conoshelioc.     Nearly 
as  great  opposition  was  manifested  to  this  innovation, 
as  has  recently  been  made  in   respect  to  Cyprcpcassis , 
but  this,   of  course,    was  to   be  expected  from   those 
conchologists  who  looked  only  for  "  well-marked  and 
absolute  divisions  :"  the  group,  however,  was  soon  taken 
up  by  the  Continental  naturahsts,  and  is  now  generally 
adopted.       Having  always  had  a  peculiar  fondness  — 
almost  a  passion  —  for  these  elegant  shells,  we  continued 
their  study,  until,  in  1827;,  our  investigations  had  pro- 
ceeded so  far  that  we  ventured  to  characterise  the  five 
leading  divisions,  or  genera.     The  great  number  of  new 
species  discovered  by  Mr.  Cummin,  added  to  others  con- 
tinually coming  before  us,  naturally  led  to  a  still  more 
close  analysis  of  the  whole.     The   result  of  this,  in  re- 
gard to  the  theory  of  variation,  was  communicated  to  the 
Zoological  Society  in  1835.*     This  theory  is  now  found 
to  pervade  the  whole  class  of  Testacea  ;  while,  in  our 
Systematic  Arrangement,   will  be   found   all  the  well- 
known   and  clearly  described  species,  distributed  under 
their  several  minor  groups.   The  MitrincE,  in  comparison 
to  the  volutes,  with  two  or  three  exceptions,  are  much 
smaller  shells,  chiefly  distinguished  by  the  smaller  size 
of  the  foot,  as  in  Mitra  episcopalis  {fig.  13.),  where  the 
proboscis  is  excessively  long ;   and  by  the  greater  length 
of  their  spire,  the  tip  of  which  is  never  papillary, f  The 

*  Proceedings  of  the  Zool.  Society,  part  iii.  p.  197 

+  Except  in  two  or  three  species  of  Mitreola,  which  blend  into  Harjmla. 


128 


SHELLS    AND    SHELL-FISH. 


PART  1. 


upper  plaits  of  the  pillar,  in  almost  all,  are  larger  than 
the  lower ;  and  the  general  form  of  the  shell  is  equally 
or  unequally  fusiform.     It  is  almost  impossible  to  esti- 


mate the  number  of  species,  as  new  ones  are  constantly 
coming  to  light ;  but  there  probably  exists  already,  in  our 
cabinets,   about  two  hundred  and  fifty,  of  which  more 
than  forty  were  brought  home  by  Mr.  Cummin  from 
the  western  coast  of  Tropical  America.     We  suspect, 
from  these  data,  that,  in  a  few  years,  the  increase  of 
known  species  will  come  near  to  300,  leaving  out  those 
that  belong   to  the   three   aberrant    genera — Mitre/la, 
Conabhelijr,  and  Mitreola.     Nearly  all  these  are  excluded 
from  the  European  seas  ;   and,  what  is  still  more  extra- 
ordinary, not  more  than  half  a  dozen  can  be  called  com- 
mon shells.       This  scarcity  of  mitres  certainly  does  not 
originate  from  the  difficulty  of  gaining  access  to  their 
haunts ;  for,   although  some  are  known  to  live  at  great 
depths*,  yet  both  MM.  Stuchbury  and  Cummin  inform 
us  that  they  generally  found  these  shell-fish  in  shallow 
water,  near  coral  reefs.     Hence  we  conjecture  that  their 
chief  metropolis  must  be  the  great  Pacific  Ocean,  where, 
among  the  countless  numbers  of  existing  islands,  and 
the  coral  foundations  of  others,  the  number  of  species 
now  unknown  may   be   nearly  equal  to  those    already 
described.      The  animals  of  a  very  few  have  been  pub- 
lished by   M.  Quoy,    in  the  invaluable  plates    of   his 
voyage;  for  the  particulars  of  which  we  have  not  suffi- 
cient space. 

(118.)   The   primary   divisions  of  the    whole  of  the 
family,  as  already  intimated,  correspond  with  those  of 

*  As  Mitra  zonnia,  which,  Dr.  Leach   says,  was  fished  up  out  of  veiy 
deep  water  near  Nice. 


CHAP.    IV. 


DIVISIONS    OF    THE    MITRES. 


129 


genera  of  the  volutes  _;  and  they  may  be  thus  briefly 

characterised  from  their 
,^Ssa^^*^^:'.-6^^^  shells.  The  most  typi- 
cal is  —  1 .  Mitra,v;here 
the  basal  whorl  is  some- 
what ventricose,  and  the 
aperture  has  no  inter- 
nal groove.  2.  Tiara 
(fig.  14.) J  having  the 
basal  whorl  contracted, 
and  the  internal  groove  distinct; — this  is  the  sub-typical 
genus.  The  3d,  or  next,  Mitrella,  resembles  the  olives 
in  being  smooth,  and  in  having  the  base  of  the  pillar 
thickened,  with  the  plaits  very  much  projecting.  In 
the  4th,  or  Conoehelijc,  the  spire  is  very  short,  the  plaits 
numerous, and  sometimes  indistinct:  whereas,  in  the  5th, 
or  Mitreola,  the  upper  plaits  are  smallest,  the  outer  lip 
inflected  and  sometimes  toothed,  and  the  spire  slightly 
papillary.  As  all  these  peculiarities  will  be  detailed  in 
the  next  division  of  our  volume,  we  shall  here  only  make 
a  few  general  observations  on  the  contents  of  the  genera  ; 
and  first,  with  regard  to 


The  Analogies  of  the  Volutins  and  the  Mitring. 


Genera  of  the 
MitrincB. 

MiTRA. 


Tiara. 


Mitreola. 


CONfEHELIX. 


Mitrella. 


■\ 


Analogical  Characters. 

rBody-wliorl  never  contracted  at 
<     the  base  ;  the  whorls  never  tur 
C     retedor  anguiated. 

fShell  turreted;  body-whorl  con-~| 
I     traded    in    the    middle;     the] 
<{      whorls  nodulous  or  sub-coro-  J* 
I      nated,     or    carinated,     larely  | 
L    smooth.  J 

rThe  upper  plaits  on  the  pillar^ 
-5  smaller  than  those  in  the  mid-  v 
C  die  ;  spire  sometimes  papillary.  J 
Spire  very  short;  plaits  very  slen-  ^ 
der,  sometimes  obsolete  ;  sur-  f 
face  generally  reticulated  or  f 
striated.  3 

r Smooth,  generally  polished;  the"^ 
-<  lower  plaits  smaller  than  the  > 
C     upper.  3 


Genera  of  the 
Volutince. 

V GLUT a. 


Cymbiola. 


Harpula. 


Volutilithes. 


SCAPHELI.A. 


K 


130 


SHELLS    AND    SHELL-FISH. 


PART  I. 


We  shall  make  no  other  commentary  upon  this  table, 
than  as  regards  the  rank  of  the  groups  in  each  column, 
which  are  thus  shown  to  he  genera.     The  sub-genera. 
of  the  Volutince,  it  will  be  remembered,  we  have  indi- 
cated, but  not  named,  because  the  species  they  contain 
are  so  few,  and  these  so  well  known,  that  it  might  be 
thought  a  needless  multiplication  of  names.     But  in  the 
present  family  the  case  is  widely  different :  as  not  one 
third  of  the  mitres  are  figured,  and  the  descriptions  of 
most  of  the  remainder  are  too  vague  to  admit  of  deter- 
mination, it  becomes  absolutely  necessary,  not  only  to 
characterise,  but  to  name,  the  sub-genera.   This  we  have 
accordingly  done,  —  confining  ourselves,  however,  to  the 
two  typical  genera,   which,  as  in  all  such  groups,   con- 
tain the  great  majority  of  the  species.       The  foregoing 
table  shows  that  Mitra  and   Tiara  are  the  two  groups 
in  question;   and,  as  the  definitions  of  their  sub-genera 
wiU  be  hereafter  detailed,    we  shall  at  once  lay  before 
the  reader  the  exposition  of  their  analogies. 


Analogies  of  the  Genera  Mitra  and  Tiara. 


Sub- gen  era  of 

Mitra. 
Internal  canal 
wanting ;  aper- 
ture smooth. 

Mitra. 


Tiarella. 
Scabricola. 
Nebularia. 
Strigatella. 


Analogical  Characters. 


Sub-genera  of 

Thiara. 

With  an  internal 

canal  ;  aperture 

striated. 


f  Spire  and  aperture  of  equallength,  "i 

<  unequally      fusiform ;      body-  > 
t     whorl  obtuse.  j 

("Shell   with   distinctly  coronated,  7 
X     acute,  or  obtuse  tubercles.  j 

f  Shell  with  numerous  elevated  ribs,  f 

<  longitudinal  in  one,  transverse  V 
C     in  the  other.  j 

("Shell  reticulated  or  cancellated  ;  7 

X     the  base  of  the  aperture  effuse.  3 

Size  very  small  ;  outer  lip  thick 

ened,    and    generally    gibbous 

within. 


\ 


} 


Costellaria. 

Tiara. 

Calliihca. 

Cancilla. 

Pusia. 


It  thus  appears  that  each  of  the  divisions,  or  sub- 
genera, of  Mitra  finds  its  representative  in  Tiara ;  and 
that,  without  a  due  regard  to  the  essential  characters 
which  distinguish  these  two  genera,  it  will  be  impossible 


CHAF.   IV.         SUB-GENERA    OF    MITRA    AND    TIARA.        131 

to  know  to  which  of  them  a  Lamarckian  Mitra  really 
belongs.  We  are  sorry,  indeed,  to  impose  so  much  trou- 
ble upon  collectors;  but  the  blame,  if  any,  must  be 
laid  upon  Nature — not  us:  for  we  merely  endeavour  to 
trace  her  steps.  But  she  does  not  stop  here.  Into  each 
of  these  sub-genera,  which  happen  to  be  full  of  species, 
she  actually  carries  the  same  principles  of  variation  ;  so 
that,  if  aU  the  shells  really  belonging  to  our  sub-genus 
Mitra,  even  as  now  restricted,  were  spread  before  the 
naturalist,  he  would  find  not  very  incipient  characters 
of  every  one  of  the  sub-genera  just  enumerated  ;  and 
this,  to  such  an  extent  as  to  justify  our  reaching  this 
conclusion,  —  that  if  the  whole  of  the  species  that  hare 
been  created  were  known,  every  Mitra  would  have  its 
counterpart,  or  prototype,  in  the  circle  of  Tiara. 
Any  naturalist  may  convince  himself  of  this,  by  look- 
ing to  the  five  sectional  types  of  the  sub-genus  Mitra, 
for  instance,  as  episcopalis,  riiffina,  punctata,  lactea.  and 
zojiata.  The  second  represents  Tiandla  by  its  crenated 
suture  ;  the  third  shov/s  us  the  roughness  of  Sca'oricola  ; 
the  fourth  the  effuse  aperture  of  Nehularia;  and  the 
fifth  the  dingy  colour  and  thick  epidermis  of  Strigatella. 
The  Mitra  terebralis  and  the  Tiara  terebralis*'  are 
counterparts  of  each  other,  and  are  only  prototypes, 
under  a  different  form,  of  the  genera  Terebra  and  Tur- 
ritella.  We  regret  exceedingly  that  we  cannot  give  as 
full  an  exposition  of  the  mitres  as  we  have  done  of  the 
volutes:  half  a  volume  would  hardly  be  sufficient.  It 
seemed  preferable  fully  to  detail  our  analysis  of  the 
first,  as  being  the  typical  group  ;  and  because,  from  the 
comparative  paucity  of  the  species,  the  natural  series  be- 
came more  difficult  to  demonstrate  than  that  of  the 
mitres.  Now,  as  the  principle  of  variation  in  each  is 
precisely  the  same,  we  have  given  only  the  results  of 

*  Of  this  shell,  Mr.  Broderip  justly  observes,  "  It  is  one  of  the  most  slen- 
der of  its  genus,  and  has  very  much  the  general  character  and  form  of  a 
Terebra  :  this  resemblance  is  increased  by  the  circumstance  of  its  having 
one  spiral  groove  more  deeply  impressed  than  the  others,  placed  at  about 
one  third  of  the  length  of  each  volution  before  the  suture."  —  Froc.  Zool. 
Soc.  part  iii.  ISoo,  p.  li:'6. 

K    2 


132 


SHELLS    AND    SHELL-FISH. 


PART  I. 


our  investigation  in  the  mitres.  Whether  we  view  the 
family  Volatidce  as  a  whole,  or  contemplate  separately 
each  of  its  divisions,  whether  large  or  small,  we  shall 
find  their  variation  uniformly  harmonising  with  what 
has  been  seen  in  \he  MuricidcB  and  the  Turhinellidce, — 
a  fact  which  every  one  will  perceive,  on  investigating 
the  following  table,  which  is  also  sufficient  to  furnish  the 
clue  even  to  the  analogies  of  the  sub-genera. 

General  Analogies  of  the  Volutid^. 


Families 

Sub-families 

Genera 

Genera 

Sub-families 

Sub-families 

of  the 

of  the 

of  the 

of  the 

of  the 

of  the 

ZOOPHAGA. 

Volutidce. 

Volutince. 

MUriJiu:. 

Muricldce. 

Turbinellidce- 

TUKBINELLII)^ 

VOLUTIN^E. 

Volula. 

Mitra. 

Cassfn.^. 

TURBINELLIXK 

MUR1CID.C 

MlTRIV^. 

Cymbiola. 

Tiara. 

MURICI-VJE. 

SCOLYMIN^. 

VOLUTID^. 

OLIVlNiE. 

Harpula. 

Mitreola. 

BuCCININiE. 

Fusing. 

Cyprjside. 

Ancillarine. 

Volutilithes. 

Con  te  helix. 

PURPURIN,!:. 

Pyrulin.e. 

Stkombid^. 

Marginelli.v^. 

ScaphcUa. 

Mitrella. 

NASSIN.E. 

Eburnin.e. 

(119.)  The  three  aberrant  divisions  of  the  volutes, 
namely,  the  Olivine,  the  ANciLLARiNyE,  and  the  Mar- 
gelling,  must  be  dismissed  in  a  few  words.  The  minor 
variations  in  each  are  very  few,  and  will  be  found  in 
the  systematic  arrangement.  The  genus  Mitrella  leads 
us  immediately  from  the  mitres  to  the  olives ;  where, 
as  in  Harpula,  the  plaits  upon  the  pillar  cover  the  whole 
length  of  the  inner  lip :  the  foot  of  the  animal  is  ex- 
cessively large,  and  sufficiently  dilated  to  fold  over  the 
greater  part  of  the  shell ;  but  the  mantle  is  not  lobed. 
The  first  genus  is  Lamprodoma* ,  which  chiefly  differs 
from  Mitrella  in  having  the  channeled  suture  so  uni- 
versal among  the  olives.  This  leads  to  the  typical 
genus  Oliva,  wherein  the  majority  of  the  species  are  still 
arranged.  Scaphula,  by  its  thick  undefined  spire  and 
ventricose  body-whorl,  is  a  complete  prototype  of  the 
melon  volutes,  and  prepares  us  for  Hiatula,  in  which  the 
characters  of  Oliva,  Scaphula,  and  Ancillaria  are  com- 
bined. The  circle  is  then  closed  by  those  small  species 
arranged  under  the  genus  Olivella,  wherein  the  base  of 

*  Lamp.  Oiiudla,  Zool.  111.  ii.  pi.  40.  fig.  I. 


CHAP.    IV.  ANCILLARIA.  MARGINELLA.  133 

the  aperture  is  only  effuse^  and  the  spire  as  much  length- 
ened^ as  in  Lamprodoma :  the  plaits  on  the  pillar,  like 
those  on  VolutiUthes,  are  reduced  to  their  minimum;  the 
two  last  are  the  strongest,  the  others  nearly  obsolete. 
It  is  by  this  particular  group  that  the  Volutid^  and 
the  TuRBiNELLiD^  are  united  ;  the  direct  passage  being 
marked  by  Olivella  hiplicata  Sw.  in  one,  and  Pseudoliva 
plumbea  Sw.  in  the  other,  {fig.  3.  at  p.  82.)  The 
olives  are  among  the  best  known,  the  most  polished,  and 
the  most  variable  shells  in  this  family.  They  swarm  in 
the  seas  of  tropical  climates,  more  especially  in  the 
East,  but  seem  altogether  excluded  from  the  European 
coasts. 

(120.)  The  forms,  or  variations,  among  the  Ancil- 
LARiN^  are  as  yet  too  few  to  render  it  necessary  to 
create  sub-divisions  :  the  beautiful  analogy  which  this 
group  bears  to  the  Pur  purines,  by  the  prominent  little 
tooth  on  the  outer  lip,  as  well  as  by  the  width  of  its 
aperture,  must  not  be  overlooked  ;  while  the  high  polish 
of  all  the  species,  the  general  shortness  of  the  spire,  and 
the  unusual  thickness  of  the  base  of  the  inner  lip,  are 
so  many  points  of  resemblance  to  the  Cyprceidce. 

(121.)  Finally,  the  MARGiNELLiDiE  are  the  smallest 
shells,  as  to  size,  in  the  whole  family :  they  are  at 
once  distinguished  by  their  thickened  outer  lip ;  but  they 
all  vary  in  the  absence  or  developement  of  the  spire 
and  of  the  inner  lip,  as  well  as  in  the  plaits  of  the 
pillar:  hence  their  genera  may  be  sufficiently  defined. 
Their  union  with  the  Volutince,  by  means  of  Scaphella 
Zebra*,  is  clearly  shown  by  our  genus  Glabella,  where 
the  inner  lip  is  either  entirely  wanting  or  but  slightly 
developed:  these  latter  conduct  to  To/^^eZ/a,  which, by  its 
obsolete  spire,  preserves  a  strong  analogy  to  the  melons. 
In  Persicola  we  have  a  prototype  of  Comehelijc ;  while 
the  typical  form,  Marginella,  has  the  inner  lip  so  much 
developed,  as  to  form  a  thickened  deposition  all  round 
the  aperture.     On  the  fifth  type  we   feel  some  uncer- 

*  Placed  among  the  Marginellce  by  Lamarck. 
K    3 


134  SHELLS    AND    SHELL-FISH.  PART   I. 

tainty  ;  but  we  think  it  is  represented  by  those  species 
which  have  the  outer  lip  gibbous  above,  analogous  to 
Voluta  Scapha  and  other  strombiform  types  ;  or  it  may 
possibly  be  Lamarck's  fossil  genus  Volvaria.  It  is  easy 
to  perceive,  however,  how  strikingly  this  sub-family, 
as  a  whole,  represents  the  Nassince.  the  Ehurnince,  and 
the  ColumbellincB,  all  which  are  prototypes  of  the 
Stro7nbid(T. 

(122.)  We  shall  conclude  our  exposition  of  this 
interesting  family  by  what  may  be  called  a  continu- 
ation of  the  last  diagram,  for  the  purpose  of  illustrating 
certain  analogies  in  regard  to  the  animals. 

Analogies  of  the  Volutid^  to  Vertehrated  and  Annulose 

Animals. 

Genera    Sub-families   Families        Tribes  of  the       Classes  of      Classes  of 

i^f  Af°       S       T^j°!  Y  Dithyra.  Aniynals.        Insects. 

Volutmcc.    Murtcidce.  Phitophaga.  ^ 

Voluta.         Cassince.       Trochidcc.    Atrachia.  Mammalia.  Aptera. 

Cymbiola.     Muriclnte.    HelicidcB.     Macrotrachia.     Aves.  Ptilota. 

Harpula.     Buccinirue.  Turbidxe.      Tubulibranchia.  Reptilia.     Annelides. 
Volutilithes.  Purpurince.  Naticidce.     Chelisoma.  Amphibia.    Vermes. 

Scaphella.    Nassince.      Haliotidce.   Branchiopoda.     Pisces.         Cirripedes. 

It  is  chiefly  with  reference  to  the  fifth  set  of  types, 
which  contains  the  longest-bodied  animals  in  all  these 
circles,  that  we  have  drawn  up  this  table.  A  pecu- 
liarity is  of  course  shown  in  the  Testacea,  by  the  pro- 
longation of  the  spiral  whorls :  hence  we  find  the 
longest-spired  volutes  are  in  the  genus  Harpula.  The 
BiiccinincB  contains  Terebra  ;  and  the  genus  Turritella 
is  the  type  of  the  Turbidce.  Continuing  this  analogy 
on  to  the  bivalves  (Dithyra),  we  have  the  long  tubular 
snake-like  shells  of  the  Tubulibranchia,  representing 
the  real  serpents  among  vertehrated  animals,  and  the 
Annelides  among  the  annulose  or  insect  tribes.  The 
excessive  developement  of  the  organs  of  locomotion,  or 
foot,  as  shown  in  the  first  set  of  analogies,  is  most  re- 
markable. But  as  a  chapter  would  be  insufficient  to 
illustrate  the  innumerable  analogies  concentrated  in  this 


CHAP.   IV.  CYPR/EIDiE,    OR    COWRIES.  135 

table,  we  must  leave  it,  as  a  fruitful   and  untrodden 
field  to  those  who  wish  to  prosecute  its  study. 

(123.)   The    passage   to  the  Cypr^id^e    is  so  well 
marked  by  those  JfarginelUncB  which  have  the  spire  com- 
pletely hidden,  as  to  leave  no  doubt  of  the  cowries  follow- 
ing the  volutes.     We  must,  for  want  of  space,  omit  the 
accounts   of  the  animals  of  the  two  typical  divisions, 
Cyprcea  and  Ovula,  now  well  known  by  the  excellent 
descriptions  of  MM.  Quoy  and  Gaimard :   suffice  it  to 
observe,  they  have  some  things  in  common  with  the 
volutes;  — the  foot  is  very  large,  and  the  tentacula  short : 
the  mantle  is  dilated  into  two  large  lobes,  almost  sufficient 
to  cover  the  shell  entirely, —  their  junction  being  marked 
by  a  pale   line  down   the  back,  where  the  colour  often 
appears  as  if  faded.      The  Cyprmnce,  or  cowries,  form 
the   typical,  and  the  OvulincE,  or  egg-shells,  the  sub- 
typical,  group.     The  former  are  well  known  as  among 
the   most  elegant  and  richly  coloured  of  the  Te^tocm; 
always  having  the  spire  concealed,  and  generally  onisci- 
form,  —  that    is,  oval,    and    flattened  beneath.       The 
species  are  particularly  numerous  in  tropical  latitudes, 
and  several  are  among  the  most  common   shells  in  our 
collections:  they  have  been  very  ably  investigated  by  ]Mr. 
Gray,  who  has  judiciously  characterised  and  named  some 
of  the  types  ;  for  they  were  all  left  by  Lamarck  in  one 
genus.  The  OvulincB  resemble  in  general  form  the  cow- 
ries ;  but  the  extremities  of  the  aperture  are  generally 
produced,  and  there  are  no  teeth  on  the  inner  lip.    Not 
having  yet  investigated  this  division,  we  shall  for  the 
present  leave  it  as  it  is,  and  merely  notice  those  which 
seem  to  be  the  aberrant  genera,  connecting  this  family, 
on  one  side,  to  the  VolutidcB,  and,  on   the  other,  to  the 
Stromhidce.     The  first  we  conjecture  to  be  the   fossil 
genus  Volvaria,  as  well  defined  by  Mr.  Sowerby  *;  while 
the  latter  union  appears  to  be  affected  by  Erato,  where 
the  general  shape  is  that  of  a  Columhella,  but  with  the 
dorsal  sulcated  line  of  Trivea :  between  this  we  are  dis- 
posed to  place,  under  the  name  of  Cylindrella,  two  or  three 

*  Genera  of  Shells. 
K    4 


136  SHELLS    AND    SHELL-FISH.  PART   I. 

small  shells  resembling  Folvaria  in  form^  but  destitute 
of  any  plaits  upon  the  inner  lip.  The  Cyprceidoi  will 
thus  form  a  group  far  less  perfect  in  its  contents  than 
the  Volutidce,  yet  sufficiently  marked  to  constitute  it 
circular. 


CHAP.  V. 

THE    PREDACEOUS    GASTROPODS  CONTINUED. THE  STROMBID^, 

OR  WING-SHELLS. 

(124.)  The  Strombid^  is  one  of  the  most  varied  of 
the  predaceous  families^  not  so  much  in  the  structure 
of  the  animals,  as  in  their  shells.  The  typical  group, 
indeed,  is  very  peculiar  in  both  respects ;  but  the 
animals  of  the  rest,  with  which  we  are  as  yet  acquainted, 
have  a  much  greater  sameness  than  would  have  been 
expected  from  the  marked  difference  in  their  habitations. 
In  regard  to  the  first,  the  most  prevalent  character 
appears  to  be  the  pedunculated  nature  of  the  eyes, 
which  are  generally  situated  about  midway  upon  the 
tentacula  —  never  at  their  base,  or  at  their  tips.  In 
the  typical  Stronibi,  these  organs  are  so  much  de- 
veloped, that  the  iris  is  richly  coloured ;  and  the  eyes 
of  some  of  the  large  species  have  been  described  to  us 
as  particularly  beautiful.  The  shells  present  every 
variety  of  the  spiral  form,  excepting  that  they  are  never 
depressed ;  yet,  throughout  the  whole,  one  character 
may  be  traced  :  the  outer  lip  is  either  enlarged,  thick- 
ened, or  expanded ;  or,  if  not  so,  the  upper  part  is 
detached  from  the  spiral  whorl,  so  as  to  form  a  wing- 
like or  angular  projection;  hence  their  common  name  of 
wing-shelh :  all  are  furnished  with  a  small  operculum, 
and  are  strictly  external  shells.  In  the  Lamarckian 
genera  Strombus,  Conus,  Columbella,  Pleurotoinu,  and 
Cerithium,  the  student  will  see  the  five  principal  types. 


CHAP.   V.  STR03IBID^.  13? 

(125.)   The  rank  of  the  group  bemg  that  of  a  family, 
its  tirst  divisions,  just  mentioned,  become  sub-families. 
1.  The  StrombiniB,  or  true  wing. shells,  having  the  outer 
lip  greatly  dilated,  with  a  lobe  at  the  base,  and  often  on 
the  summit  also,  of  the  outer  Up  ;  the  spire  being  always 
more  or  less  elevated.    2.  The  Conince,  or  Cones,  w^here 
the  spire  is  so  depressed  as  to  be  turbinated,  and  scarcely 
raised   above  the  body-whorl :   the  aperture  is   always 
smooth ;    the  outer    lip   without    any    lobe,    and    only 
slightly  detached  above.    3.  The  Colmnbellince,  or  dove- 
shells,   small    in    size,  and  with   short-pointed   spires  ; 
the  outer    lip   is   thick,   turned  inwards,   more  or   less 
toothed  on  its  edge,  and  gibbous  above  ;  there  are  also 
tuberculated  teeth  at  the  base  of  the  inner  lip,  but  no 
regular  plaits.     4.   The  PJeui'otomhKP,  or  slit-shells, — 
so  called  from  a  deep   lobe,  or  slit,  at  the   top  of  the 
outer   lip  :   the   spire,  in  general,  is  very  long,  and  the 
shells  themselves  often  spindle-shaped.     5.   The  CeH- 
thincB,  called  club-shells,  from  their  clavate  form :   the 
body- whorl  is    not    much   larger  than  the   one   which 
precedes    it  ;    but    the    outer    lip  is  slightly  detached 
above,  and  then  much  dilated  ;  the  basal  canal,  which 
is  always  very  short,  is  generally   more  or  less  turned 
backwards. 

(126.)  These  primary  divisions  appear  to  form  a 
circular  series,  and  to  be  united  in  the  following  man- 
ner : — Commencing  with  the  StrombincE,  we  pass  from 
them  to  the  Cerithince,  by  means  of  that  well-known 
shell  the  S.  pes-pelicani  of  Linnseus,  which,  in  its  im- 
mature state,  before  its  lip  has  expanded,  might  easily 
be  mistaken  for  a  young  Cerithium.  Next  to  these 
latter,  Lamarck  places  the  Pleurotomince ;  their  junc- 
tion being  formed  by  his  Clavatula,  and  the  genus 
Potomis  :  with  these,  again,  a  union  is  rendered  abso- 
lutely perfect  with  the  Columhince,  by  means  of  certain 
genera  now  defined  for  the  first  time :  others  of  the 
ColiimhirifB  so  strikingly  resemble  small  cones,  that  but 
for  a  close  inspection,  they  could  not  be  distinguished. 
From  the  cones  we  pass  to  the  singular  genus  TereheUum, 


138  SHELLS    AND    SHELL-FISH.  PART  I. 

which  brings  us  once  more  to  the  Strombincp  ;  and  ter- 
minates the  series.  We  shall  now  take  each  of  these 
sub-families  in  succession,  and  lay  before  the  reader 
the  result  of  the  closest  analysis  we  have  been  able  to 
give  them. 

(127-)  The  Strombin^e,  or  true  wing-shells,  are  obvi- 
ously the  pre-eminent  typical  group  ;  and  consequently 
stand  at  the  head  of  the  family.  The  great  expansion 
of  the  outer  lip  in  all  the  genera,  save  one  (^Strombidea*), 
which  connects  them  to  Terehellum,  is  their  best,  and, 
indeed^  their  only  general,  distinction.  The  genera  are 
five  :  StromhuSy  Sti'ombidea,  Rostellaria,  Aporrhais,  and 
Pterocera ;  all  of  which  are  easily  recognised.  The 
most  typical,  perhaps,  is  Pterocera,  where  the  outer  lip 
is  expanded,  in  mature  age,  into  very  long  claw-like 
processes,  which  gives  them  something  the  appearance 
of  scorpions,  with  the  legs,  on  one  side,  stretched  out, 
and  those  of  the  other  concealed  ;  but  their  chief  cha- 
racters seem  to  rest  on  the  basal  lobe  of  the  outer  lip 
being  turned  inwards,  and  generally  toothed.  This 
character,  hitherto  overlooked,  has  caused  two  of  the 
sub-generic  types  to  be  placed  with  the  Lamarckian 
Strombi ;  and  hence  the  latter  has  been  overburdened 
with  shells  which,  we  think,  do  not  naturally  belong  to 
it.  The  first,  or  typical,  form  is  seen  in  P.  lanibis,  where 
the  processes  of  the  lip  are  all  pointed  in  one  direction  ; 
and  the  basal  canal,  which  is  considerably  lengthened, 
is  curved  only  on  its  terminal  half.  The  second  is  the 
P.  millipeda, — differing  from  the  last,  not  only  in  the 
greater  number  of  the  processes,  but  in  those  adjoining 
the  spire  being  more  united  together  at  their  base  ;  or, 
in  other  words,  the  divisions  are  not  so  deeply  cleft. 
This  type  prepares  us  for  the  third,  which  has  all  the 
characters  of  Pterocera,  except  that  the  lateral  pro- 
cesses are  wanting,  and  the  upper  are  only  indicated  by 
deep  lobes  :  the  only  example  yet  known,  is  the  shell 
we   formerly  figured  under  the  name  of  Sty'ombus  sinii- 

*  Represented  by  Str.  urceus  and  its  allies. 


CHAP.   V.  PTEROCERA.  STR03IBUS.  139 

atus,  but  which  we  now  remove  to  the  present  genus. 
This  we  also  do  with  the  Strombus  latissimus  of  authors, 
which  constitutes  our  fourth  type.  This  remarkable 
shell  immediately  follows  the  Pterocera  sinuata  ;  and 
although  the  digitations  no  longer  appear,  they  are 
slightly  indicated  by  little  folds  :  the  side  of  the  outer 
lip,  as  in  all  the  other  types,  is  broadly  reflected  inwards. 
In  the  fifth  and  last  form,  as  seen  in  P.  chiragra,  the 
digitations  are  again  developed ;  but  they  are  fewer  in 
number,  and  of  nearly  equal  length.  In  this  type,  also, 
the  basal  channel  is  recurved  outward ;  and  the  sinus 
on  the  lip  is  so  remote  from  the  base,  as  to  admit  of  an 
intervening  process. 

(128.)  The  restricted  genus  Strombus  follows  that 
of  Pterocera  ;  it  is  distinguished  by  the  outer  lip  being 
entire,  much  dilated,  and  always  furnished  with  sinu- 
osities, or  lobes,  both  above  and  below  :  the  base  is 
short,  and  slightly  turned  upwards.  In  this  genus  there 
are  five  distinct  modifications.  The  Pterocera  sinuata 
leads  us  immediately  to  the  first  type,  which  is  com- 
posed of  S.melanostomus,  pacificus,  Auris-Dianw  hinn., 
and  Lamarckii*  In  all  these,  we  trace  the  last  rem- 
nant of  the  character  oi  Pterocera, —  namely,  the  folding 
back  of  the  outer  lip,  which  is  particularly  conspicuous 
in  our  ^S".  melanostomus  and  Pacificus  :  the  upper  part, 
also,  is  prolonged  into  a  lengthened  process.  As  a  group, 
it  is  at  once  known  by  the  basal  canal  being  turned 
back,  as  in  the  Cerithince,  or  rabbit-shells.  From  these, 
by  means  of  S.  tricornis  and  Gallus,  we  are  brought 
to  the  beautiful  pink-mouthed  S.  gigas,  and  the  rare 
iS".  Goliathus,  where  the  lip  may  be  said  to  have  attained 
its  majcimum.  In  Acclpiter  and  Canai'um,  it  assumes 
the  shorter  and  more  wing-like  form  of  the  type  which 
succeeds  this  :  all  these,  with  Strombus  granulatus,  &c., 
and,  finally,  Epidi'omus,  seem,  to  us,  to  constitute  a 
second  type  of  form,  w^herein  the  outer  lip  is  particularly 
large   and   spreading,  yet  without   that   short  sinus,    or 

*  I  know  not  who  has  affixed  this  name  to  what  was  considered  the 
smooth  variety  of  Auris-Diarue. 


140 


SHELLS    AND    SHELL-FISH.  PAKT   1. 


lobe^  which  is  so  prevalent  in  the  next  group.  This 
lobe  is  most  conspicuous  in  S.  lentiginosiis,  where,  in 
fact;,  there  are  two  ;  as  is  the  case,  also,  in  our  S.  Gallus 
and  tuherculntns  ;  but  in  minimus,  variabilis,  &c.,  the 
lobe  is  less  apparent.  Yet,  in  all  these,  the  outer  lip, 
although  large,  is  not  reflected,  but  takes  a  curve  in- 
wards. The  fourth  type  is  seen  in  ^S".  gibherulns,  which 
is  remarkable  for  the  shortness  and  distortion  of  the 
spiral  whorls,  and  the  very  slight  expansion  of  the  outer 
lip  :  it  is  chiefly  remarkable,  however,  for  a  thickened 
deposition  of  enamel  at  the  top  of  the  inner  lip,  analo- 
gous to  that  in  Nassa,  Oliva,  &c.  These  are  connected 
to  the  last  by  Lulmanus,  which  has  the  distorted 
spire,  but  not  the  other  characters,  of  gihherulus.  The 
fifth  and  last  type  is  seen  in  the  Stromhus  succinctus, 
remarkable  for  the  prolongation  of  the  lip,  very  high 
upon  the  spire,  so  that  it  becomes  a  perfect  represent- 
ation, in  this  group,  of  Rostellaria. 

(129.)  The  next  genus  is  Stromhidea, —  a  name  we 
give  to  all  those  small  shells,  which,  like  S.  urceus  and 
its  congeners,  have  the  outer  lip  merely  lobed  at  the 
base,  without  being  detached,  or  dilated  above.  We 
take  some  blame  to  ourselves,  for  not  having  long  ago 
perceived  that  these  shells  were  not  true  Strombi  ;  but 
we  had  then  only  analysed  the  family  in  part ;  and,  as 
usual  in  such  cases,  we  subsequently  found  that  we 
were  in  error.*  The  Strombidea,  in  short,  are  proto- 
types of  the  ColumbellincB ;  and  so  strong  is  this 
analogy,  that  our  S.  crassilabis  was  sent  to  us  as  a 
Columbella. 

(130.)  The  genus  Rostellaria  contains  some  few 
of  the  most  elegant  and  costly,  if  not  the  most  beautiful, 
shells  in  this  family  :  it  is,  therefore,  very  interesting, 
even  to  the  conchologist ;  but  it  is  particularly  so  with 
reference  to  its  types.  The  primary  distinction  of  all 
these  shells,  —  few  in  number,  but  singularly  varied, — 
is  a   slender  channel,   thickened   on  each   side,   which 

*  1  allude  to  the  article  regarding  the  Sirombidcc  in  the  second  series  of 
the  Zoological  Illustration)!. 


CHAP.   V.  ROSTELLARIA. APORRHAIS.  141 

ascends  from  the  aperture  nearly  to  the  top  of  the  spire  : 
the  shell  has  much  of  the  shape  of  a  typical  Pleurotoma  ; 
the  basal  channel  being  more  or  less  lengthened.     To  this 
genus  we  are  led  by  the  Stromhidea  tridentata,  — the  only 
Stromhus  Avhich  gives  us  at  once  the  outer  lip  of  Ros- 
tellaria  cwvirostris,  with  all  the  other  characters  of  our 
genus  Stromhidea,     The  first  type  of  Rostellaria  is  seen 
in  those  elegant  shells,  R.  curvirostris  and  rectirostris, 
where  the  siphon  is  moderate :   the  outer  lip  is  hardly 
dilated,   since  its  margin  is  merely  divided  into  short 
processes.      The  rectirostris  is  of  great  rarity ;   but  of 
still  greater  value  is  that  which  forms  the  second  type  ; 
indeed,  it  seems  to  be  known  only  by  the  figure  of  Chem- 
nitz, and  has  been  altogether  omitted  by  Lamarck  :   it 
is  channeled  to  the  tip  of  the  spire ;  while  the  outer  lip, 
without  being  much  dilated,  is  divided  into  a  number 
of  short  spine-like  processes.      In  the  third  type,  Ros- 
tellaria macroptera,  the  upper  siphon  is  equally  long  ; 
but  the  lip,  instead  of  being  cleft,  is  entire,  semicircular, 
and  dilated  to  an  enormous  size.     In  these  two  last  tvpes, 
in  fact,  we  have  the  greatest  developement  of  the  lip;  and 
hence  we  may  expect  a  declension  in  the  succeeding  forms. 
Such  is  accordingly  seen  in  Rostellaria  columbata,  where 
the  lip,  although  dilated  and  very  broad,  does  not  extend 
more  than  half  way  up  the  spire,  although  it  is  rather 
lengthened  into  the  same  sort  of  lobe  as  that  in  Strombus 
pacificus.      There  is  still  a  great  difference  between  R. 
columbata  and  the  first  type  we  noticed ;    but  our  fifth 
brings  them  together  :  this  is  formed  of  the  small  species, 
four  or  five  in  number,  among  which  the  elegant  little 
Grignon  fossil,  Rostellaria  fissurella  Lam.,  is  the  best 
known.     In  these  shells,  the  lip  is  no  longer  dilated,  nor 
is  it  extended  up  the  spire  ;   they  lose,  in  short,  one  half 
of  the  characters  of  their  own  genus,  and  in  the  same  pro- 
portion assume  those  of  Strombus,  —  thus  becoming  the 
most  aberrant  type  of  the  sub-family;  while  their  station 
between  R.  curvirostris  and  columbata  is  apparent  to  the 
most  unscientific  eye. 

(131.)  The  last  genus  is  that  of  I)a  Costa's  Apor- 


142 


SHELLS    ANI>    SHELL-FISH. 


PART   I. 


rhais,  and  the  only  example  yet  known  is  the  pes-peli- 
cani,  or  pelican's-foot  strombus.  That  it  has  a  close 
affinity  to  Rostellaria  colinnhata  is  evident  from  the  outer 
lip  being  dilated ;  but  then  it  has  four  lobes,  or  rather 
flattened  and  digitated  processes,  something  similar  to 
Fteroceras  chiragra ;  and  it  deserves  attention,  that 
these  are  the  only  two  in  the  family  which  have  the 
basal  channel  assuming  precisely  the  form,  size,  and 
structure  of  the  other  processes  of  the  outer  lip  :  on  the 
other  hand,  it  has  no  distinct  lobe  at  the  base,  its  mar- 
gin is  not  inflected,  and  the  upper  part  advances  upon 
the  first  spiral  whorls  ; — in  all  which  it  shows  an  affinity 
to  Rostellaria.    In  its  young  state,  however,  {fig.  15.  a)  it 

has  quite  a  different  appear- 
ance; for  its  form  is  then  so 
much  like  that  of  a  young 
Cerithium  (b),  that  none 
but  a  scientific  observer 
could  detect  the  diff^erence. 
Equally  related  in  this  man- 
ner to  three  different  ge- 
nera, we  look  upon  this 
type  as  connected  to  Ros- 
tellaria  on  one  side,  Pte- 
rocera  on  another,  and  to 
the  Cerithince  on  a  third. 
All  these  affinities  are  more  peculiarly  apparent  in  its 
three  different  stages  of  growth;  so  that,  when  quite 
young,  it  is  a  Cerithium  ;  when  the  outer  lip  is  half 
expanded,  it  is  a  Rostellaria  ;  and,  in  adult  age.  it  puts 
on  the  very  aspect  of  a  Pterocera.  Here  we  close  our 
evidence  on  the  affinities  and  natural  arrangement  of 
this  family, 

(132.)  Having  now  gone  through  the  affinities,  we 
turn  to  the  analogies  of  the  Stromhinci'.  They  are  ob- 
viously the  typical  division  of  the  whole  family;  and,  as 
such,  should  represent  within  their  own  circle  all  the 
other  divisions  :  this  will  be  apparent  in  the  following 
tabic  :  — 


CHAP.   V. 


ANALOGIES    OF    THE    STROMBIN^. 


143 


Genera  of 
Strombin^. 

Pterocera. 
Strombus. 

Strombidea. 
Rostellaria. 

Aporrhais. 


Analogies  of  the  Genej'a  of  the  ^trombi^:  je. 

Analogies. 


Sub-families  of  the 
Strombid^. 


Outer  lip  greatly  dilated,  andlobed.  Strombin^. 

rOuter  lip  detached  above,  and  en-  7  rQ»Tj^„ 
I    tire.  j 

rOuterlipnot  detached,  but  gib- '^ 

•<     bous  ;  both  lips  thickened,  and  >CoLUMBELLiN5i. 

C.     generally  striated.  j 

vShell  long,  slender,  fusiform.  Pleurotomin^e. 


'Shell  club-shaped  when  young; 
channel    very  short,    and 
sted  on  one  side. 


r Shell  c 
<     the 
C.     twist 


Ijc 


ERITHIN^. 


These  variations  take  place  in  precisely  the  same  or- 
der as  that  in  which  the  relations  of  affinity  occur ;  for 
each  of  these  columns  is  a  circular  group,  —  the  genus 
Aporrhais  being  as  much  connected  to  Pterocera  as  to 
Rostellaria.  Turning  to  the  other  group,  we  perceive 
the  very  same  affinity  between  Cerithium  and  Strombus, 
through  the  medium  of  Aporrhais,  as  between  Cerithium 
and  Pleurotoma.  The  resemblance  between  Strombidea 
and  the  typical  ColumheUincE,  again,  cannot  be  mistaken  ; 
for  the  outer  lip  of  both  forms  a  sort  of  angle  or  gib- 
bosity, altogether  peculiar  to  these  two  groups.  This 
remarkable  thickening,  in  short,  of  the  lips  in  Strombidea, 
renders  the  genus  a  prototype  of  the  Colunibellince,  as 

well  as  of  the  Mar - 
ginellince.  Rostella- 
ria and  the  Pleuro- 
tomincE  are  the  only 
fusiform  groups  in 
the  whole  family ; 
while  the  likeness 
of  a  young  Apor- 
rhais to  the  Ceri- 
thincB  need  not  be 
dwelt  upon.  The 
resemblance  between  such  shells  as  Strombus  Luhuanus 
{fig.  1().  a),  when  young  (6),  and  Conns  amadis  (c), 
and  others,  is  so  great,  that  an  unpractised  eye  can 
hardly  tell  the  difference. 


144 


SHELLS    AND    SHELL-FISH. 


PART   I. 


(133.)  Our  next  comparison  will  be  between  the 
types  of  form  in  the  genus  Pterocera,  and  the  genera 
of  the  StromhincB. 


Analogy  of  the  Types  of  Form,  in  the  Genus  Pterocera. 


Types  of 
Pterocera. 

Lambis. 
MilHpeda. 

Sinuata. 
Latissimus. 

Chimsra. 


Analogies. 


Basal  canal  greatly  lengthened. 

Basal  canal  short. 
f  Outer  lip  thickened,  and  inflected  7 
(_     inwards ;  basal  canal  truncate.  J 

f  Outer  !ip  extending  to  the  apex  > 
X     of  the  spire,  and  entire.  J 


1 


Canal  resembling  the  digitated 'J 
processes  of  the  lip,  and  turned  > 
on  one  side.  j 


Genera  of 
Strombin.e. 

Pterocera. 
Strombus. 

Strombidea. 

RosTELLiVRIA. 

Aporriiais. 


In  such  small  groups  as  these,  we  cannot  expect  the 
analogies  to  be  very  strong;  a  faint  resemblance  is  all 
that  exists  —  and  all,  indeed,  that  is  necessary.  Yet  it  is 
remarkable  how  perfectly  P.  latisslmns  corresponds  to 
the  RosteUaria  macroptera  in  its  excessively  large  outer 
lip,  which,  in  both  shells,  runs  up  to  the  top,  and  even 
spreads  far  beyond  the  apex  of  the  spire. 

(134.)  The  analogies  of  the  genus  Stromhns  are  nume- 
rous, and,  in  some  measure,  too  complicated  to  be  here 
introduced :  it  will  be  sufficient  to  remark,  that,  besides 
the  five  leading  divisions  or  types  of  form,  there  may  be 
discerned  indications  of  another  set  of  secondary  types  ; 
so,  that,  if  such  groups  were  better  understood  (as  no 
doubt  they  will  be  hereafter),  some  cf  them  may  be 
found  to  contain  representations  of  the  primary  genera 
of  the  St7'otiibin(e,  no  less  than  of  its  leading  divisions. 
The  time,  however,  is  not  yet  come  for  such  an  elaborate 
study  of  analogies  as  this  implies  ;  and  we  shall,  there- 
fore, merely  place  before  our  readers  the  five  divisions 
of  the  genus,  which,  as  already  specified,  seem  to  be 
represented  by  the  five  following  shells:  —  Sfromh7<s 
Atiris-Dkinrp,  yiyas,  lentig'mosus,  gihhernhis,  and  suc- 
cinvius.      All  these  are  among  the  most  common  species. 


CHAP.  V. 


CONINE,    OR    CONES. 


145 


and,  as  such,  may  be  readily  procured  by  every  student 
who  feels  interested  in  these  inquiries. 

Analogies  of  Types  of  the  Genus  Strombus. 


Species  of 
Strombus. 

S.  Auris-Diarus. 
gigas. 
lentiginosus. 

gibberulus. 

succinctus- 


Analogies. 

f  Channel  bent  ;  inner  lip  spread-  1 
\     ing  on  the  spire.  J 

Outer  lip  reflected,  entire. 

5  Outer  lip  inflected,  divided  above;  1 


f  Outer  lip  slightly  or  not  at  all7 
X     expanded.  _) 

fA  long  siphon  running  up  the  7 
i     spire.  j 


Divisions  of  the 
Stroynbince. 

Aporrhais. 

Strombus. 

Pterocera. 

Strombidea. 

rostellaria. 


By  arranging  the  intermediate  species  between  each 
of  these  types,  the  whole  would  exhibit  another  set  of 
relations^  as  well  as  a  series  of  connecting  links  ;  thus 
Auris-DiancB  is  followed  by  a  little  group  composed  of 
tricornis,  gallus,  and  Peruvianus,  which  connect  the  for- 
mer shell  with  S.  gigas :  but  the  student,  after  these 
hints,  will  find  no  great  difficulty  in  following  up  the 
theory  himself. 

(135.)  The  next  genus,  Rostellaria,  is  particularly 
interesting  to  the  lover  of  analogies,  inasmuch  as  all  the 
types  are  not  only  existing,  but  are  of  that  definite 
character  which  leaves  no  doubt  of  their  true  import. 


Analogies  of  the  RosTELLARiiE. 


Species  of 
Rostellaria . 


Serrata  Sw.* 

Macroptera. 
Columbata. 

Rectirostris. 
Fissurella- 


\ 


\ 


Analogies. 


Outer  lip  reaching  to  the  tip  of 
the  spire,  and  divided  into  pro- 
cesses. 

Outer  lip  very  large,  and  entire. 

'Outer  lip  hardly  attached  to  the  7 

spire,  and  dilated  into  a  lobe.     5 
■  Outer  lip  not  dilated  at  the  top,  } 

and  not  extending  on  the  spire.  3 
Outer  lip  hardly  dilated,  but  the" 

siphon  ascending  to  the  apex  I 

of  the  spire  ;  the  margin  \vith-( 

out  teeth-like  processes. 


Genera  of 
Stromb/ncc. 

Pterocera. 

Strombus. 
Aporrhais. 

Strombidea. 
Rostellaria. 


*  Figured  in  Chemnitz,  pi.  195  A.  fig.  1869. 
L 


146  SHELLS    AND    SHELL-FISH.  PART  I. 

It  thus  appears  that  each  type  of  the  Rostellarice,  as 
arranged  according  to  their  affinities,  turns  out  to  be  a 
representation  of  one  of  the  genera  of  the  Strombince  : 
and  these  analogies  are  so  perfect,  that  it  appears  to  us 
absolutely  impossible  they  could  be  more  complete  —  at 
least,  in  regard  to  the  shells ;  although  they  would  be 
even  more  beautiful,  when  accompanied  by  a  corre- 
sponding relation  in  the  animals.  R.  rectirostris  is  the 
fourth  type,  and  not  the  common  curvirostris  ;  because 
this  latter  is  intermediate  in  structure  between  the 
former  and  R.  fissurella. 

(136.)  We  feel  persuaded,  that  if  the  concluding 
volumes  of  the  elaborate  work  of  Lamarck  had  not  been 
finished  ^^  under  the  eyes  of  another,"  because  their 
celebrated  author  had  become  blind,  we  never  should 
have  seen  our  Rostellaria  cancellata  and  canalis  placed 
in  his  genus  Strombus.  No  species,  in  fact,  either  of 
Strombus  or  of  Pterocera,  so  far  as  we  know,  occur  in 
a  fossil  state.  It  appears  hardly  necessary,  in  so  limited 
a  group,  to  impose  sub-generic  names  of  these  types  ; 
for  if  one  is  named,  all  should  be  so.  Such  designations 
are  not  necessary  to  facilitate  research,  when  the  whole 
genus  contains  not  more  than,  perhaps,  a  dozen  species. 
With  the  mitres,  the  cones,  and  the  land  snails,  &c.,  the 
case  is  very  different :  such  groups  contain  hundreds  of 
species ;  and  by  designating  their  sub-genera  under 
patronymic  names,  most  material  help  is  afforded,  in  all 
ways,  to  minute  research,  or  to  general  views. 

(137-)  The  connection  of  the  Conine,  or  cones,  with 
the  StrombincE,  is  effected  by  our  new  genus  Strombidea 
in  the  latter,  and  Terehellum  in  the  former.  The  affini- 
ties of  these  two  genera  we  pointed  out  many  years  ago, 
by  the  publication  of  a  shell  which  actually  unites  the 
characters  of  both  *;  and  Lamarck  entertains  no  doubt 
of  the  close  connection  of  Terebellum  to  Conus.  Tere- 
helium,  in  short,  merely  represents  the  olives  in  this 
circle,  without  having  any  real  affinity  with  them  ;   but 

*  strombus  dubius.  See  Taylor's  Phil.  Mag.  61.  No.  301.  May,  1823.  This 
will  now  be  our  Strombidea  dubia.  Specimens  are  in  the  rich  collection 
of  Mr.  StanJord. 


CHAP.    V. 


CONINiE,    OR    CONES. 


147 


of  their  animals,  nothing,  we  believe,  is  yet  known. 
The  true  cones,  from  their  beauty,  are  the  favourite 
shells  of  conchologists.  Nearly  all  are  natives  of  tro- 
pical climates,  where  they  constitute  one  of  the  most 
extensive  races  of  the  carnivorous  shell-fish.  The  mouth 

is   a   short    proboscis    (^fig.  l6.  a), 
which    in     one    genus    (^Coronaxis 
Sw.)   has  the   margin   simply   cir- 
cular,   while   in  the  other  (Conns 
Linn.)  it  is  laciniated,  or  divided  into 
a    circular  fringe  of   little   points, 
analogous  to  the  lips  of  the  Trochi- 
dce.     In  both  these  genera,  the  ten- 
tacula  {h)  are  short,  cylindrical,  and 
nearly  obtuse,  with  the  eyes  small, 
and  but  slightly  developed,  placed 
half   way  on    their   external  side  : 
the  foot  is  small,  rather  broad,  trun- 
cate in  front,  and  rounded  behind, 
where  it  bears  a  small  oblong  oper- 
culum,  sufficient  only  to  close  the 
detached  part  of  the  top  of  the  outer 
lip.      The  respiratory  siphon  (c)  is  well  developed,  but 
its  form  seems  to  vary  in  the  sub-genera :  in  some,  it  is 
thickest  at  the   base   (as  in  C.  bandanus*)  ;  in  others 
(C.  arenatus),  it  is  uniformly  cylindrical. t     Lamarck 
describes  no  less   than  181  species,  besides  nine  fossil; 
but  we  question  if  there   are   not  more  than   230,   or 
perhaps   250,  species  already  in  collections.     Such  an 
immense  assemblage  of  mere  species,  as  they  now  stand, 
fully  justifies  us  in   giving  patronymic   names  to  the 
sub-genera,  and  arranging  them  in  distinct  groups  ,•  a 
plan  long  ago  recommended  \,  but  never  yet  acted  upon. 
By  separating  the  coronated   from  the  smooth  species, 
nothing  material  is  gained  ;  for  although  they  constitute, 
in  reality,  two  genera,  the  internal   relations  subsisting 
between  them  are  passed  over  ;  and  these,  in  our  opinion, 

*  Voy.  d' Astrolabe,  pi.  52.  fig.  7.,  here  copied^"'.  16. 

t  Ibid.  pi.  52.  fig.  8.  X  Sow.  Genera  of  Shells,  article  Comts. 

L    2 


148  SHELLS    AND    SHELL-FISH.  PART   I- 

are  the  most  important  object  to  be  illustrated  ;  while 
the  mere  collector  has  no  additional  help  to  the  no- 
menclature of  the  specieSj  more  than  he  now  has. 
Long  and  procrastinated  attention  to  these  beautiful 
shells,  together  with  the  invaluable  delineations  of  their 
animals  by  M.  Quoy,  has  now  enabled  us  to  give  the 
following  exposition  of  the  genera  and  sub-genera.* 

Analogies  and  Characters  of  the  Sub-genera  o/"  Con  us 

and  CoRONAxis. 

C0Nt;S.  CORONAXIS. 

Shell  not  coronated.  Shell  coronated. 

C.  litteratus.  f  Shell  ponderous  ;  basal  whorl  not  ^  nandanus 

Virgo.  \     contracted    near    the    suture;  \     marmoreus 

generates.  (     spire  in  general  flattened.  J 

striatus.  f  Shell  ponderous  ;  basal  whorl  con-  T  jij-cnntus 
stercus-mnscarum. <     tracted  near  the  suture;  spire  >     cedo-nulli 

ammeralis.  C     short,  pointed.  j 

bullata.  r Shell  light;  basal  whorl  ventri- i 

textile.  3     cose  ;  aperture  eS'use  ;  the  base  {  Tulina 

auratus.  j     hardly  notched ;    spire    short,  C 

aulicus.  C     pointed,  concave.  } 

nussatella.  C  Shell  sub-conic,  cylindrical,  trans- 1 

glans.  <      versely  grooved;  spire  elevated,  >^sp^r? 

terebra.  C     thick,  convex,  generally  obtuse,  j 

amadis.  f  Shell    conic,   light,   often   trans- ^ 

gramiis  ^     versely  striated;  spire  concave  f  ^..„^ 

duplicatus.  j     elevated,  and  ponited  ;    outer  ( 

australis.  C     lip  deeply  sinuated  above.  j 

This,  perhaps,  is  one  of  the  most  remarkable  instances 
of  analogy  yet  brought  before  the  reader ;  inasmuch  as 
the  characters  used  as  analogies  are  those  only  by  which 
the  shells  of  each  group,  or  sub-genus,  of  Conns  and 
Coronaxis,  can  be  defined.  Nothing  additional,  in  fact, 
can  be  added  to  separate,  for  instance,  the  sub-genus  of 
Conus,  whose  type  is  C.  litteratus.  from  its  represent- 
ative, C.  marmoratus,  in  the  genus  Coronaxis :  so  per- 
fect are  these  resemblances,  that  we  do  not  actually 
know  where  the  two  groups  join  and  unite.  As  to  the 
circularity  of  each,  there  cannot,  we  apprehend,  be  the 
least  doubt ;  for  the  intervening  shades  of  difference  are 
so  gentle,  that  we   hardly  know  where  one   type    ends, 

*  The  names  of  the  types  are  in  Italic  ;  those  of  the  annectant  species  in 
Iloman. 


CHAP.  V.  GENERA    OF    THE    CONINE.  149 

and  the  next  begins.*  Such  only  are  natural  and  per- 
fect groups  :  they  are  the  delight  of  the  philosophic 
naturalist^  and  the  torment  of  the  mere  nomenclator.  As 
Conus  is  the  most  numerous  in  species,  so  it  is  the  most 
perfect  in  these  gradations^  by  which  its  five  sub-genera 
are  blended  into  one  circle.  The  superior  heaviness 
which  belongs  to  the  two  typical  divisions  in  each,  is 
very  singular,  and  may,  probably,  be  owing  to  the 
internal  volutions  of  their  shells  not  being  so  much  ab- 
sorbed as  in  the  other  types  :  a  simple  section,  however, 
will,  no  doubt,  explain  the  cause. 

(138.)  Whether  Conus  dormitor,  and  other  fossil 
species,  really  constitute  the  analogous  genus  in  this 
circle  to  the  PleurotomcB,  cannot  be  determined,  as  no 
recent  species,  that  we  know  of,  have  been  discovered  : 
we  shall,  however,  regard  them  in  this  light  under  the 
generic  name  of  Conorbis.  The  only  remaining  genus 
is  that  of  Conella,  hitherto  overlooked  among  the  di- 
versified shells  placed  in  Columhella  by  Lamarck,  where 
they  continue  to  the  present  day.  They  are  all  very 
small,  and  perfectly  resemble  Cones  in  their  shape ;  but 
they  may  be  easily  known  by  the  outer  lip,  which  ad- 
vances upwards  on  the  spire,  and  is  marked  internally 
by  distinct  elevated  striae.  This  is  a  most  interesting 
group  ;  for  it  not  only  connects  this  and  the  succeeding 
sub-family  of  Columbellims  in  the  most  satisfactory 
manner,  but,  at  the  same  time,  it  preserves  an  affinity, 
on  the  other  hand,  to  Conorbis. 

(139.)  The  Conine,  thus  arranged,  form  themselves 
into  the  five  following  genera,  analogous  to  the  primary 
divisions  of  the  Strombidce.  The  genus  Conella  (^  fig.  17. «.) 
€onnects  this  and  the  last  sub-family. 

*  There  is  one  rule,  however,  which  we  have  found  quite  sufficient  for 
this  purpose.  If,  of  three  characters  of  a  given  type,  a  species  possesses 
only  one,  and  that  but  slightly  developed,  the  probability  is,  that  it  really 
belongs  to  the  next  type ;  or  the  question  may  be  decided  by  the  law  of  re. 
presentation.  Every  natural  and  perfect  group,  of  whatsoever  value,  con- 
tains representations  of  all  the  other  four  groups  of  its  own  value  in  that 
circle  which  unites  them  all.  Thus,  it  will  not  be  difficult  for  the  natural- 
ist to  discover,  in  that  sub-genus  which  includes  Conus  striatus,  represent- 
ations (among  the  species)  of  all  the  other  four. 

L  3 


150  SHELLS    AND    SHELL-FISH.  PART  I. 


Analogies  of  the  Conine,  or  Cones. 

Genera  of  the  4„nir,ci^<i  Sub-families  ol 

Conine.  Analogies.  Strombin*. 

CoNUs.  Spire  short,  smooth.    Typical.  Conin,^. 

CoRONAXis.  Spire  coronated  or  nodulous.  Strombin^. 

Terebellum.  ?  Cerithin^. 

CONORB.S.  [  ^tSuSip"  ^^^"  ''  ^'^  '"'  "1  P— OTOMI... 

CoNELLA.  Outer  lip  striated  internally.  Columbellin^. 

The  third  analogy,  not  heing  apparent  in  the  shells, 
probably  may  be  traced  in  the  animals.  But  this  is  not 
very  material,  since  the  whole  arrangement  is  founded 
upon  affinities,  and  all  the  other  analogies  are  perfect. 

(140.)  The  C0LUMBELLIN.E,  or  dove-shells,  although 
of  a  small  size,  rather  smooth,  and  without  any  dilation 
of  the  outer  lip,  have,  nevertheless,  very  much  the 
aspect  of  little  wing-shells ;  this  impression  originates 
in  the  thickened  angle  or  hump  on  the  upper  part  of 
the  outer  lip  ;  a  character  which  is  seen  in  no  other 
group  but  that  of  Strombidea,  and  in  certain  MarginellcB, 
—  both  which,  in  fact,  are  legitimate  representatives  of 
Columbella.  According  to  Guilding,  the  animals  of 
this  group,  like  that  of  ConuSy  have  the  operculum  so 
very  small  as  often  to  escape  detection. 

(141.)  The  result  of  an  attentive  analysis  leads  us 
to  arrange  the  whole  of  these  shells  under  the  five  fol- 
lowing genera  :  —  1.  We  retain  the  name  of  Columbella 
to  the  C,  mercatoria,  and  the  other  European   species, 
where  the  crenated  teeth  of  the  reflected  inner  lip  ex- 
tend its  whole  length,    and    are    regularly    graduated, 
those  on  the  inner  being  but  slightly  developed.     2.  In 
Pusiostoma,  the  teeth  on  both  sides  of  the  aperture  are 
much    more    developed ;  those    on    the    outer    lip    are 
crowded,  very  thick,  and  only  occupy  the  middle  por-  . 
tion.     Both  these,  but  particularly  the  last  genus,  have 
the  top  of  the  lip  so  gibbous,  as  to  form  a  prominent  and 
even  projecting  angle  :   they  constitute  the  sub-typical 
and  the  typical  groups,  and  consequently  exhibit  the 


CHAP.   V, 


GENERA    OF    THE    COLUMBELLIN^. 


151 


characters  of  the  ColumbellhuB  in  the  highest  perfection. 
The  three  aberrant  genera  are  more  diversified.  Thus, 
Conidea  {fig.  17.  h)  has  the  general  form  of  a  short  fusi- 
form mitre  (like  Mitra  contracta*),  or  that  of  a  cone 
with  the  spire  as  long,  or  longer,  than  the  body -whorl, 
but  still  with  the  volutions  thickened  at  the  suture,  and 
the  aperture  narrow  :  there  are  a  few  tooth-like  stria?  on 
the  inner  part  of  the  outer  lip ;  but  it  is  not  thickened 
in  the  middle :  the  inner  lip  forms  an  elevated  ridge  at 
the  base  ;   parallel  to    which  is  a  longitudinal  elevated 


17 


fold  slightly  crenated  ;  but  the  tuberculated  teeth  on  the 
pillar  are  entirely  wanting.  In  some  species  the  spire  is 
rather  lengthened,  with  the  aperture  widened :  and  this 
change  brings  us  to  the  4th  genus,  Nitidella  (c),  where 
the  inner  lip  and  its  fold  totally  disappear  ;  the  upper 
part  of  the  pillar,  or  rather  that  side  of  the  whorl  which 
forms  the  apertm-e,  is  flattened,  as  if  pared  down  arti- 
ficially (as  in  Purpura)  ;  the  base  is  finely  striated,  as 
in  Ancillaria,  and  is  terminated  by  a  distinct  plait 
(sometimes  two),  such  as  is  seen  in  Volutilithes.  All 
these  resemblances  point  to  one  type  of  structure,  and 
intimate  this  to  be  the  most  aberrant  sub-genus  of  the 
Columbellince.  There  are  many  species,  but  all  small ; 
the  most  common  of  which  is  the  Columbella  nitida  of 
Lamarck  t,  a  little  "lYest  Indian  shell,  in  almost  every 
collection :  the  outer  lip  is  either  smooth  or  slightly 
striated  within;  but  although  the  edge  is  slightly 
thickened,  it  is  never  contracted  in  the  middle  —  nor 
is  the   margin,    although  inclining   inwards,  decidedly 


*  Zool.  \\\.  1st  Series. 


f  Nitidella  Tnarmorata.Sv!.  {fig.  17.  c.) 
L    4 


152  SHELLS    AND    SHELL-FISH.  PART   I. 

inflected  :  hence  these  shells,  on  a  cursory  glance,  much 
more  resemble  the  Buccinints  than  the  Columhellince : 
they  are  almost  always  smooth,  and  generally  shining. 
The  5th  and  last  genus  is  Crassispira.  {fig.  !?•  d-) 
These  are  also  small  shells,  having  the  outer  lip,  externally, 
almost  as  thick  as  in  Pusiostoma,  but  with  a  distinct 
notch  at  the  top ;  this  notch  is  in  the  same  position,  but 
not  near  so  deep,  as  in  the  club-shaped  Pleurotomince  : 
like  them,  also,  the  spire  is  rather  long,  and  the  base 
very  short ;  so  that  at  first  sight  they  remind  us  of  very 
small  Cerithince  :  the  aperture  is  contracted  both  above 
and  below,  but  wide  in  the  middle  ;  thus  being  precisely 
the  reverse  to  that  of  Pusiostoma,  which  is  contracted  in 
the  middle,  and  wider  at  the  extremities.  These  shells, 
of  which  there  are  several  species,  are  known  at  once 
from  the  PleurotomirKs,  to  which,  however,  they  lead, 
by  the  outer  lip  being  inflexed  and  much  thickened, 
and  by  the  sinus  not  extending  beyond  the  margin.  In 
such  species  as  unite  with  Pusiostoma,  the  aperture  is 
slightly  toothed,  and  much  contracted  ;  while  in  those, 
on  the  other  hand,  which  pass  into  Nitidella,  the  shell 
is  more  fusiform,  the  mouth  more  effuse,  and  the 
outer  lip  thin.  These  variations,  which  would  otherwise 
be  unaccountable,  are  fully  explained  by  the  relations 
that  this  singular  little  genus  bears  to  the  two  adjoining 
groups  of  the  Columhellince,  and  render  it  one  of  the 
most  natural  in  the  whole  family. 

Analogies  of  the  Genera  of  the  CoLUMBELLiNja. 

Genera  Typical  Genera 

of  the  Analogies.  of  the 

ColimihcUina:.  Stro7nbidce. 

Columbclla.  Sub-typical ;  shell  coniform.  CoNUS. 

TThe  outer  lip  often  forming  a  si-T 

Nitidella.  \      nus   at  the  upper  part ;  aper-  >        Pleurotoma. 

C.     ture  effuse.  J 

„     .,  ("Aperture   very  narrow;    whorls  7         tvt  .w,^. .,,.,. . 

Contdea.  {     ihickencd  at  their  suture.  5        Marginella. 

This  table  is  drawn  up  for  the  especial  purpose  of 


CHAP.  V.        ANALOGIES    OF    THE    COLUMBELLINiE.  153 

explaining  the  singular  mixture  of  characters  concen- 
trated in  this  suh-family  ;  for  the  only  one  by  which 
all  its  genera  are  bound  together,  consists  in  the  outer 
lip  being  invariably  inflexed,  and  either  striated  or 
toothed.  Some  of  the  analogies  are  weak,  others  strong ; 
but  as  they  follow  each  other  in  the  same  series  as  that 
of  the  primary  divisions  of  the  family,  this  regularity, 
of  itself,  is  quite  sufficient  for  our  purpose.  The  sin- 
gular tuberculated  tooth  at  the  bottom  of  the  aperture, 
in  several  of  the  NitidellcB,  their  flattened  pillar  ter- 
minated by  an  internal  fold,  the  absence  of  a  definite 
inner  lip,  and  the  effuseness  of  the  aperture,  are  all 
explained,  by  the  following  table. 

Analogies  of  the  Genera  of  the  Columbellin^. 

Genera  Sub-families  Genera        Sub-families 

of  the  Analogies.  of  the  of  the  of  the 

COLUMBELLIN^.  VoLUTIN.E.  VOLUTINS.        MuRICID^. 

Columbella.         Sub-typical,  Mitra,  Cymbiola.         Muricin^. 

Pusiostoma.         Typical.  Voluta.  Voluta.  Cassin^e. 

r  Outer    lip     much  "i 
Crassispira.      <     thickened,     and  >  Marginella,  Scaphella.        Buccinin^s. 

C     notched  above.    3 

fObsolete    plaits   at") 

I      the  base  of  the | 

Nitidella.         \     ^mf/o'   ^'^t^^l^I^  f>  Ancillaria.    Volutilithes.  PiniPURiN;E. 

times  with  an  in-  j 

l^     ternal  tooth.        J 

r Spire  short;  inner T 

Ccmidea.  <     lip  much   deve- >Oliva.  Harpui.a.  Nassin^. 

C    loped.  J 

(142.)  But  the  ColumbellincE  possess  other  resem- 
blances, among  which  that  to  the  mitres  has  been  thought 
so  strong,  as  to  induce  the  early  reformers  of  conchology 
to  place  them  both  in  the  same  genus  ;  hence  it  was 
taken  as  a  resemblance  of  affinity.  We  have  seen,  how- 
ever, by  the  analysis  of  the  Folutidcp,  that  this  idea  is 
erroneous.  The  impression  undoubtedly  originated  in 
the  strong  resemblance  between  the  strombiform  division 
of  the  mitres,  forming  our  genus  Harpella,  and  the 
typical  Columhell(S.  Yet  even  this,  although  a  striking 
instance  of  relationship,  is  only  analogical,  as  will  be 
seen  more  clearly  by  the  following  table : — 


154  SHELLS    AND    SHELL-FISH.  PART  I. 

Analogies  of  the  Strojibid^  and  the  Mitring. 

Families  of  the  ^     ;     •     j /^j,         j  Genera  of  the 

STROMBID.E.  Analogical  Characters.  Mitiunze. 

Stkombus.  Shell  generally  rugged.  Tiara. 

CoNus.  (■Shellsmooth,  destitute  of  protuO         ^. 

t     berances  on  the  body  whorl.      3 

CO.UMB.....  [  ^^S;J'P,;-^  Tnated.^'^'""''  ]         "^rpella. 

Pleuroto.ma.  [  Often  coniform  ;  tip  of  the  outer]         Cona^kelu. 

I     lip  sinuated.  3  lutw-^n  . 

Ceiutuium.  ?  Miirella. 

(143.)  Without  going  further  into  particulars,  we 
may  observe  that  these  tables  afford  strong  collateral 
evidence  that  the  strombiform  structure  —  at  least,  in  this 
order — is  one  of  the  primary  types  of  form,  which  is 
repeated  and  represented,  under  every  possible  modifi- 
cation, in  almost  all  the  groups  hitherto  noticed. 

(144.)  The  Pleurotomin^  is  our  next  sub- family. 
The  perfect  gradation  of  forms  which  connects  this 
remarkable  group  with  the  cones,  wiU,  it  is  presumed, 
remove  all  doubts  as  to  its  supposed  affinity  with  the 
FusincB.  Nothing,  indeed,  short  of  the  evidence  here 
adduced  would  have  satisfied  us  that  Lamarck  was  in 
error  in  approximating  Pleurotoma  to  Fusiis  :  so  strong 
are  early  impressions  and  preconceived  opinions.  The 
discovery,  however,  of  the  genus  Crassispira  brings 
into  this  group,  by  means  of  the  new  genus  Brachytoma, 
a  small  group  of  shells,  having  the  aspect  of  some 
Lamarckian  Fusmce,  but  with  the  basal  canal  longer, 
and  the  spire  shorter,  than  Crassispira.  One  of  the  most 
typical  has  been  aptly  named  Stromhiformis* ;  it  is  tur- 
reted  and  nodulous,  with  the  notch  at  the  top  of  the 
outer  lip  short,  and  nearly  semicircular, — hardly  more 
developed,  in  fact,  than  it  is  in  Crassispira.  There  are 
several  other  species,  mostly  nodulous,  and  having  the 
general  appearance  of  such  shells  as  Fusus  Syracusensis. 
We  next  come  to  the  typical  genus  Pleurotoma,  where 
the  channel  is  so  much  lengthened  as  to  be  little  shorter 
than  the  spire.     These  appear  to  be  succeeded  by  a  group 

*  Sow.  .Manual,  fig.  381. 


CHAP.  V.     GENERA  OF  THE  PLEUROTOMIN^.      155 

to  which  we  have  retained  Lamarck's  original  name  of 
Clavatula  ;  it  has  the  long  narrow  slit  oi  Pleurotoma,  but 
with  a  very  short  canal.  Following  this  comes  Clavi- 
cantha,  having  the  canal  equally  short ;  but  the  sinus,  or 
notch^  instead  of  being  linear  and  long,  is  short  and 
wide,  the  surface  is  rough,  and  the  whorls  either  coro- 
nated with  prickles  or  with  compressed  nodules  resem- 
bling spines.  The  last  genus  is  Tomella,  w^hich  has  the 
spire  and  canal  nearly  equally  fusiform  ;  but  the  former 
is  of  very  few  whorls^  and  the  inner  lip  is  considerably 
thickened  within,  where  it  joins  the  outer  lip.  In  these 
five  genera,  all  the  varied  species  of  this  group  will 
arrange  themselves  :  the  two  typical  are  recognised  by 
the  length  and  narrowness  of  the  sinus,  which,  in  the 
three  aberrant  genera,  is  short  and  wide.  Clavicantka 
is  a  very  remarkable  form,  inasmuch  as  it  seems  pro- 
bable that  echinata  and  auricultfera  *  are  fluviatile  shells, 
Lamarck  describes  them  as  PleurotomcB ;  and  not  having 
seen  them,  we  take  his  authority  for  the  fact ;  but  we 
might  almost  question  whether  they  do  not  belong  to 
Potomis,  which  is  the  first  genus  in  the  Cerithince, — 
so  intimately  do  these  sub-families  appear  connected. 
Nearly  the  whole  of  these  shells^  like  the  mitres,  are 
scarce  ;  and  yet  the  species  are  numerous.  They  chiefly 
come  from  the  Indian  seas,  and  other  warm  latitudes. 

(145.)  The  situation  and  the  genera  of  the  Pleuro^ 
tomincB,  thus  determined  by  analysis,  offer  some  very 
curious  analogies  which  merit  our  special  notice.  The 
sinus,  which  gives  them  the  appearance  of  having  the 
outer  lip  ddated,  although  it  is  really  not  so,  is  only  a 
modification,  as  we  believe,  of  the  wider  sinus  nearly 
in  the  same  part  of  the  outer  lip  in  Stroinbus;  and 
these,  again,  are  but  different  modifications  of  the  same 
part  in  the  typical  cowries,  where  the  outer  lip  forms  a 
sinus  before  it  joins  the  umbilicus  or  depression  of  the 
spire.  That  this  fissure  is  intended  to  admit  the  'pro- 
trusion of  some  particular  organ  of  the  animal,  is  un- 

*  Ency.  Meth.  pi.  439.  figs.  8.  10. 


156 


SHELLS    AND    SHELL-FISH.  PART  I. 


questionable;  but^  until  we  know  what  the  structure  of 
this  animal  really  is,  nothing  further  can  be  determined. 
A  similar  notch  is  found  in  the  genera  lanthina,  Scicu- 
rella,  and  Pleurotomaria,  among  the  phytophagous  fami- 
lies ;  and  the  slit,  in  certain  Emarginulce,  may  probably 
be  analogous.  By  disposing  the  genera  in  the  order  they 
have  here  been  placed,  some  interesting  analogies  will 
come  to  light. 

Analogies  of  theVhi^VROTOMiNJE  and  the  Strombid^e. 

Genera  of  the  yi     i     ■    ?  m         .  Genera  of  the 

Pleurotomin^.  Analogical  Characters.  Strombid^. 

Brachitoma.  [  Outer  lip  gibbous  and  ascending ;  ^        strombidea. 

i     inner  generally  thickened.  J 

Pleurotoma.  [Typical;        canal      considerably  j         Pterocera. 

i     lengthened,  as  long  as  the  spire.  J 

Clavatula.  Sub-typical ;  canal  short.  Strombus. 

Clavicantha.  Canal  very  slight.  Aporrhais. 

ToMELLA.  Inner  lip  considerably  thickened.  Rostellaria. 

(146.)  We  now  turn  to  the  Cerithin^,  or  club- shells, 
the  last  division  of  the  family.  They  merit  this  name, 
not  merely  from  their  shape,  but  from  having  the  whorls 
encircled,  either  with  obtuse  spines,  nodules,  or  granu- 
lations. To  M.  Quoy  we  are  indebted  for  a  knowledge 
of  the  animals  of  three  of  the  genera,  each  of  which  has 
some  marked  and  peculiar  character,  —  more  so,  even, 
than  their  shells.  Hitherto,  with  the  exception  of 
Potomis  and  Pirena,  they  have  been  placed  in  one 
genus.  These  two,  from  being  covered  with  a  strong 
epidermis,  are  presumed  to  be  fluviatile,  or,  at  least, 
living  in  the  estuaries  of  rivers  ;  the  rest  are  found  in 
marine  but  generally  shallow  depths,  and  often  in  pools 
left  by  the  tide.  The  species  are  numerous,  both  in  a 
recent  and  fossil  state,  particularly  in  the  newest  form- 
ations, where  some  are  stated  to  occur  precisely  simi- 
lar to  those  now  living.  The  whole  of  these  shells  have 
a  very  long  spire,  a  small  body-whorl,  and  the  outer 
lip  considerably  dilated.  The  first  genus  is  T5rongniart's 
Potomis,  which  may  be  called  the  coronated  type,  be- 
ing encircled  with  obtuse  spines  and  granulated  points  ; 


CHAP.  V.  GENERA    OF    THE    CERITHIN^.  157 

the  basal  canal  is  scarcely  developed^  so  that  it  merely 
forms  a  sinus  ;  the  epidermis  is  strong,  and  of  a  rich 
fulvous  brown,  beneath  which  the  shell  is  white.  The 
typical  genus  Cerithium  appears  to  follow  next,  chiefly 
disting-uished  by  its  short  and  nearly  straight  canal  : 
the  operculum  is  oblong  and  ear-shaped,  and  the  pillar 
smooth.  These  almost  insensibly  glide  into  Rhino- 
clavis — well  distinguished,  however,  by  the  shell  having 
a  distinct  plait  on  the  pillar ;  the  basal  canal  fully  de- 
veloped, and  turned  backwards ;  and  by  the  operculum 
being  perfectly  circular.  These  are  very  elegantly 
marked  shells  :  the  colour  is  generally  white ;  and  the 
surface  is  often  reticulated  into  little  asperities,  some- 
thing like  those  on  a  file.  To  these  succeed  Terehralia, 
generally  of  a  black  colour  (as  representing  the  Mela- 
niancp),  of  a  large  size,  and  having  the  outer  lip  so 
much  developed,  that  in  almost  all,  when  fully  grown, 
it  actually  joins  the  other,  and  leaves  only  a  circular 
opening  for  the  respiratory  siphon  of  the  animal :  this 
siphon,  as  shown  in  the  admirable  figures  of  M.  Quoy, 
assumes  the  shape  of  a  radiated  star,  which  occupies 
the  perforation,  but  does  not  protrude  beyond  it :  the 
tentacula  are  very  long  ;  and  here,  for  the  first  time, 
we  begin  to  see  the  commencement  of  that  high  deve- 
lopement  of  the  eyes,  for  which  the  next  groups,  or  the 
PterocercB  and  the  Stromhi,  are  so  much  distinguished  : 
the  operculum,  as  in  Rhinoclavis,  is  round ;  but  there  is 
no  plait  upon  the  pillar,  and  the  basal  canal  hardly  pro- 
jects. The  genus  Pirena  *  completes  the  circle,  by 
showing  us  a  truncated  based  Cerithium,  with  the  sinus 
of  a  Pleurotoma.  These  shells,  like  Potomis,  are  flu- 
viatile  ;  and  thus  we  return  to  the  point  from  whence 
we  began  :  the  variations,  however,  are  so  few_,  that  the 
analogies  are  not  striking. 

(147-)  That  the  Cerithince  pass  into  the  StromhincE , 
by  means  o{  Aporrhais,  we  have,  individually,  no  doubt  : 
we    ground    this    belief    more    upon     the    similarity 

*  Ferussac  has   most  unaccountably  joined  this  very  beautiful  and  dis- 
tinct type  with  Melanopsis. 


158  SHELLS    AND    SHELL-FISH.  PART  I. 

of  their  animals_,  than  of  their  shells ;  and  yet,  when 
we  look  to  the  young  shells  of  Aporrhais,  and  of  certain 
Terebralicp,  they  might  very  readily  be  placed  in  the 
same  genus  :  the  cuts  (^fig.  15.)  already  given  at  p.  142. 
will  bring  this  fact  more  prominently  before  the  reader. 
We  are  not  so  confident,,  however,  in  regard  to  the  abso- 
lute affinities  of  certain  species  of  Potomis,  which  have 
the  aperture  oval,  and  the  basal  channel  almost  oblite- 
rated :  they  may,  indeed,  be  the  connecting  links  between 
Pol.  muricata  and  the  genus  Clavicantha  ;  but  until  La- 
marck's Pleurotoma  echinata  and  auriculifera  are  better 
known,  some  doubt  must  hang  over  them :  on  the  other 
hand,  this  is  the  point  of  union  between  the  two  great 
tribes  of  the  Zoophaga  and  the  Phytophaga  ;  so  that  the 
very  first  genus  which  we  should  have  to  notice,  if  we 
followed  the  thread  of  affinity  in  this  direction,  would 
be  that  of  Melania,  in  the  family  of  the  Turhidce, —  be- 
ing precisely  that  to  which  these  aberrant  species  of 
Potomis^  with  an  oval  aperture,  would  seem  to  belong. 


CHAP.  VI. 

ON    THE    PHYTOPHAGOUS    TRIBE    OF    SHELL-FISH. THE    PRIMARY 

DIVISIONS  OR  FAMILIES. THE  HELICID,^,  OR  LAND  AND  FRESH- 
WATER   SNAILS. 

(148.)  The  second  great  tribe  of  the  gastropod  shell- 
fish is  that  to  which,  after  the  illustrious  Lamarck,  we 
apply  the  name  oi  Phytophaga,  since  they  not  only  sub- 
sist upon  animal,  but  also  vegetable,  substances  :  they 
are  easily  known  from  the  truly  carnivorous  tribe,  by 
being  destitute  of  the  respiratory  siphon,  and  in  the 
mouth  not  being  retractile,  or  prcboscidiform.  In 
regard  to  the  shells,  the  differences  are  equally  well 
defined.  From  the  absence  of  the  respiratory  tube,  the 
aperture  is  round  and  entire,  or  at  most  is  only  slightly 
notched  in  such  genera  as  unite  the  two  groups.     The 


CHAP.  VI.    THE  PHYTOPHAGA  GENERALLY.        159 

whole  are  regular  spiral  shells, — a  character  by  which 
they  are  separated  from  the  Scutihranchia,  or  limpets. 
The  great  majority  are  external  shells,  and  all  but  one 
small  group — the  slugs  and  their  representatives, — have 
their  habitation  sufficiently  large  to  contain  the  entire 
body.  Their  modes  of  breathing  and  propagation  are 
various,  and  greatly  diversified  even  in  genera  close  to 
each  other  ;  so  that  nothing  can  yet  be  determined  of 
a  general  nature  on  these  points.  Although  the  greater 
part  of  the  Helicidce,  or  snails,  live  upon  land,  and 
therefore  breathe  differently,  a  portion  of  the  same 
family  live  in  fresh  water  ;  and  even  some  of  the  slugs 
appear  to  be  found  only  on  the  sea  shore  :  the  rest  of 
the  tribe,  excepting  the  Melaniance,  are  all  marine. 

(149.)  The  secondary  divisions  or  families  are  first 
distinguished  by  the  formation  of  their  animals,  and 
secondly,  by  the  nature  of  the  shells  :  this  latter  mode, 
however,  will  lead  to  great  confusion,  if  not  regulated 
by  the  former ;  since  there  are  many  genera  in  different 
families,  Avhose  shells  are  nearly  of  the  same  form, 
although  inhabited  by  very  different  mollusks.  As  this 
will  become  evident  when  we  enter  into  their  details, 
we  shall  at  once  characterise  the  chief  divisions.  The 
first,  or  the  most  typical,  are  the  Helicidcs,  which  in- 
cludes the  testaceous  land  snails,  the  naked  slugs,  and 
the  pulmonary  fluviatile  shells.*  The  second,  or  Tro- 
chidce,  are  entirely  marine  :  the  shell  is  almost  always 
perlaceous  ;  the  body  of  the  animal  is  furnished  with 
lateral  filaments,  and  its  mouth  with  lips,  as  in  the 
last ;  and  the  shells  of  both  are  turbinated  and  spiral. 
The  third,  or  Haliotidce,  are  known  by  their  flat  ear- 
shaped  shells,  having  only  the  rudiment  of  a  spire,  and 
without  any  pillar ;  hence  they  may  be  even  called 
spiral  limpets.  The  fourth  is  the  Naticidfe,  or  nerits, 
where  the  spire  also  is  very  small,  but  the  pillar  is 
always  thick  ;  the  exposed  part,  or  inner  lip,  often  very 
broad;    and   the  animal    slug-shaped.       The  fifth,   or 

*  This  group  corresponds  with  a  few  trifling  exceptions,  to  the  Pulmo- 
naria  of  the  Eegne  Animal.. 


160 


SHELLS    AND    SHELL-FISH. 


PART   I. 


TurbidcB,  can  only  be  characterised  effectually  by  their 
animals  :  they  bear  a  close  resemblance^  in  their  eyes, 
tentacula,  and  mouth,  to  the  Zoophaga,  and  several  of 
the  genera,  as  Turbo,  Ampullaria,  &c.,  are  provided 
with  the  same  sort  of  siphon  :  the  shells  themselves  are 
all  more  or  less  spiral,  and  exhibit  some  of  the  most 
elongated  forms  in  the  whole  tribe. 

(150.)  The  slight  degree  of  analogy  between  the 
families  of  this  tribe  and  the  zoophagous  Gasteropoda 
will,  no  doubt,  be  strengthened  hereafter,  when  the 
animals  of  each  are  better  understood. 


Analogies  of  the  Phytophagous  and  Zoophagous  Gas- 
teropoda. 


Families  of  the 
Phytophaga. 

Helicid^. 
Tbochid-e. 

Haliotid^. 
Naticid.e. 

TURBID/E. 


Analogical  Characters. 


Families  of  the 
Zoophaga. 

MURICID^. 
TURBTNELLID.E. 


Typical. 

Sub  typical. 
TFoot  enormously  large  ;  tentacula  i 
<     very  short ;  spire  of  the  shell  >     Volutid^e. 
C     very  small.  3 


f  Shell   highly  polished,  partly  or  7 
i      entirely  covered  by  the  animal.  3 


Cypr^id.b. 


r Animal  carnivorous;  mouth  pro-T 

\     bosciform,  with  a   respiratory  ?■     Strombid.e. 

t  sir  ^ 


siphon. 


Without  dwelling  upon  *these  points,  therefore,  we 
shall  take  a  detailed  survey  of  each  of  the  families. 

(151.)  The  Helicid^e  is  one  of  the  most  remarkable 
families  in  the  whole  order  of  the  Gasteropoda,  in  as 
much  as  it  is  the  only  one  of  the  truly  testaceous  divi- 
sions, wherein  we  find  moUusks  entirely  naked  closely 
and  intimately  united  to  others  which  have  perfectly 
formed  shells.  To  separate  the  naked  slugs  from  such 
as  begin  to  have  the  rudiments  of  a  shell,  and  these 
latter,  again,  from  others,  like  the  garden-snails,  whose 
habitation  is  sufficiently  large  to  contain  them,  would 
be  such  a  violation  of  nature  as  no  writer  has  yet  at- 
tempted ;  we  must,  therefore,  include  them  in  the  same 
family.  We  may  account  for  this  apparent  anomaly, 
by  supposing  that,  as  this  is  the  pre-eminent  type  of  the 
\thyto\i}\digo\xs  Gasteropoda,  nature,  so  to  speak,  has,  more 


€HAP.   VI.  HELICID^,    OR    SNAILS.  l6l 

distinctly  than  in  any  others^  pointed  out  the  mode 
which  she  pursues  in  the  development  of  all  her 
groups.  Commencing  from  the  most  simple  form,  she 
gives  us  the  first  germ  of  the  limaciform  structure  in 
the  extraordinary  genus  Herpa,  hereafter  noticed.  From 
this  point,  as  it  were,  she  makes  two  diverging  series  ; 
the  one  to  the  right  hand,  through  the  terrestrial  slugs ; 
the  other  to  the  left,  through  the  semi-aquatic  slugs 
and  the  freshwater  snails :  and  these  two  series,  after 
passing  through  numerous  links,  finally  meet  in  the 
pupaceous-formed  shells,  constituting  the  genera  of 
Pupa  and  Clausilia.  It  is  by  this  theory  we  account 
for  the  actual  presence  of  naked  mollusks  among  the 
Helkidd';  and  in  this  manner  do  we  consider  that  the 
whole  form  a  circular  group,  the  particulars  of  which 
will  be  more  clearly  stated  hereafter. 

(152.)  The  Helicid^  are  the  only  animals  of  the 
Testacea  which  breathe  atmospheric  air.  From  this 
circumstance  they  have  been  considered,  by  some,  in 
the  light  of  a  distinct  order  ;  but  their  close  and  inti- 
mate connection  with  the  Turhidce  on  one  hand,  and 
even  with  the  Trochido'  on  the  other,  clearly  shows 
their  situation  to  be  intermediate,  and  that  they,  there- 
fore, only  constitute  a  family  group.  The  respiratory 
organs  of  these  animals  simply  consist  of  a  moderate- 
sized  oval  aperture,  placed  under  the  reflected  edge  of 
the  mantle,  which  can  be  dilated  or  contracted  at  plea- 
sure ;  hence  there  are  no  branchia,  but  merely,  ac- 
cording to  Cuvier,  "  a  network  of  pulmonary/  vessels, 
which  spread  over  the  parietes  and  pulmonary  cavity." 
The  number  of  tentacula  is  variable,  according  to  the 
different  groups  ;  but  they  are  usually  four, —  two  long 
and  two  very  short ;  the  former  bear  the  eyes  at  their 
extremities,  but  these  organs  are  only  so  far  developed 
as  to  appear  like  black  points.  So  far  as  we  yet  know, 
the  greatest  uniformity  pervades  the  animals  of  all  the 
HeliciiKS,  or  turbinated  land-snails,  so  that  the  minor 
Uvisions  rest  entirely  on  the  structure  of  their  shells  ; 
but  in  the  spiral  snails    (or   the   sub-family  AchatintF) 

M 


162 


SHELLS    AND    SHELL-FISH. 


PART  I. 


both  the  animals  and  the  shells  are  more  diversified. 
Hence,  while  scarcely  any  thing  has  yet  been  done  in 
determining  the  genera  and  sub-genera  of  the  Helicino',, 
nearly  all  those  of  the  Achat'uKB  have  been  named  and 
defined.  It  is  time,  however,  to  quit  these  general 
remarks,  and  proceed  to  the  sub-divisions  of  the  family. 
(153.)  We  arrange  the  whole  of  this  group  under 
the  five  following  families,  which  may  be  thus  de- 
fined: —  1.  the  Heliciuip,  or  testaceous  snails,  having 
perfect  turbinated  shells  more  or  less  depressed  ;  the 
aperture  entire,  but  without  teeth.  2.  The  Achatinee, 
or  spiral  snails,  the  spire  of  whose  shells  is  elongated 
and  conic.  3.  The  LimnacinKB,  or  river-snails,  having 
only  two  depressed  or  flattened  tentacula,  and  no  oper- 
culum. 4.  the  Limacinrp,  or  slugs,  having  either  no 
shell,  or  one  much  too  small  to  contain  the  body.  And 
5.  the  Lucernince,  or  terrestrial  volutes,  where  the  shell 
is  orbicular,  depressed,  or  flattened,  and  the  aperture 
furnished  with  distinct  teeth.*  That  the  foregoing 
series  is  probably  the  natural  one,  may  be  inferred  from 
the  following  table  of  analogies  : — 


Analogies  of  the  HELiciDiE. 


Sub-families 

of 
Helicidcs. 


Analogical  Characters. 


Families 
of  tile 
Phytophaga. 


Helicin.e. 
achatin^e. 

LiMNAClNJL. 
LlMACIN,E. 

LUCERNIN^. 


C  Spire  most  generally  with  the  >  helicid.e. 
i      whorls  depressed.  J 

Spire  mostly  produced.  Trochid^. 

Outer  lip  considerably  dilated.  Turbid.e. 

Animal  mu(;ii  larger  than  its 

Naticid.c 


shell,  the   sides   of   which, ( 
where  it  exists,  are  enve-( 
loped  in  its  mantle. 
Depressed,  or  the  spire  very  ^ 
small;    aperture  furnished  vHahotid^. 
L     with  plaits.  J 

These  analogies  are,  of  course,  only  appl 
types  of  each,  and  are  intended   to  be  so 


Families 

of  the 

Zoophaga. 

TURBIXELLID^. 

MuRICIDyli. 
StROMBID/E. 

CYPR.EID.E. 
VOLUTin^. 

i  cable  to  the 
understood  : 


*  The  injustice  of  the  attempt  made  by  M.  de  Feru>sac  to  substitute  a 
new  and  artilivial  nomenclature  of  his  own  for  X\\q  Ihiicidie,  antl  so  tu 
cancel  the  previous  generic  names  of  Lamarck,  Draparnau(i,and  of  all  his 
predecessors,  is  without  jtarallcl  in  this  or  perhaps  any  deiiartment  of  zoo- 
Jogy,  and  can  only  be  e<iualled  by  the  confusion  it  has  caused. 


CHAP.  VI.  THK    HELICIN.E.  1 63 

we  have  stated  them  merely  as  a  preliminary  step,  to 
show  the  general,  not  the  particular,  resemblance  of 
the  primary  groups.  The  extreme  difficulty  attending 
such  an  analysis  of  the  Helicincs  and  the  Lucernince,  as 
is  necessary  to  determine  the  sub-generic  types,  will 
prevent  us,  for  the  present,  from  entering  into  the  de- 
tails of  these  two  groups  so  fully  as  we  shall  do  in  regard 
to  the  others.  We  commence  with  the  Helicin^,  as 
the  most  typical  group  ;  but,  from  the  above  cause,  its 
analysis  will  be  less  minute  than  that  of  the  other 
divisions. 

(154.)  The  typical  sub-family  of  Helicin^,  although 
more  numerous,  perhaps,  than  any  of  the  land -shells, 
has  received  less  attention,  in  regard  to  its  natural  di- 
visions, than  any  group  of  the  same  rank.  This  has 
probably  originated  in  two  causes  ;  the  entire  similitude 
that  runs  through  the  animals,  and  the  little  variation, 
of  a  decided  and  very  prominent  nature,  observable  in 
the  shells.  Nevertheless,  a  closer  attention  leads  to  the 
belief  that  this  group,  within  itself,  will  be  found  as 
diversified  in  its  modifications  as  any,  —  less  obtrusive, 
indeed,  but  promising  the  same  results,  when  thoroughly 
analysed,  as  in  all  natural  groups.  As  a  whole  they 
are  immediately  known  from  the  Lucernince,  or  land- 
volutes,  by  never  exhibiting  a  discoid  shell  furnished 
with  plaits  or  teeth  :  the  aperture  of  one  division,  indeed 
(^Pupa),  has  these  appendages  ;  but  then  the  form  of 
all  the  shells  is  spiral  and  elongated,  and  cannot  there- 
fore be  confounded  with  the  Lucernino'.  The  Helicid<^, 
perhaps,  are  best  distinguished  by  the  aperture  being 
without  teeth  and  transversely  oval, — a  shape  which  re- 
sults from  the  depressed  form  of  the  body-whorl,  which^ 
in  the  Achatiiife,  is  always  oblong  ;  and  this  character  is 
the  more  important,  because  it  is  preserved  even  in  such 
genera  as  Geotrochus,  whose  spire  is  often  as  conical  and  as 
much  produced  as  that  of  the  Bulimi.  It  is  also  to  be  ob- 
served that,  with  very  few  exceptions,  these  half-spiral 
snails  have  the  tips  of  the  spires  very  obtuse  and  even  flat- 
tened; whereas,  in  thQAchathife,  they  are  always  pointed 

31    2 


164 


SHELLS    AND    SHELL-FISH.  PART   I. 


and  comparatively  slender.  Our  analysis  of  the  Helicincp 
not  havinj^  been  yet  completed,  we  are  only  acquainted 
with  the  four  following  genera  ;  the  fifth,  which  should 
intervene  between  Helicella  and  Pupa,  being  yet  unde- 
termined. In  the  first,  or  Helix  proper,  we  have  the 
great  proportion  of  shells  usually  so  called,  of  which 
the  Helix  hortensis  is  a  good  example  ;  they  are  strictly 
turbinated  shells,  the  spire  being  very  slightly  elevated  ; 
the  body-whorl  ventricose  ;  the  aperture  without  teeth  ; 
and  the  base  of  the  pillar  never  separated  from  the  outer 
lip  :  this  is  the  typical  genus.  The  second,  or  sub- 
typical,  is  Geotrochus,  where  the  spire  is  always  elevated, 
and  composed  of  more  than  four  whorls  *,  generally  of 
five,  and  sometimes  of  six:  the  typical  species  are  trochi- 
form  ;  but  the  sub- genus  Pithohelix  puts  on  the  aspect 
of  a  Bulimus  or  Achatina.  The  third  is  Pupa,  where  the 
spire  reaches  its  full  development,  and  the  aperture 
becomes  nearly  circular  :  by  this  character  Pupa  may 
be  readily  distinguished  from  Clausilia  and  all  its  sub- 
ordinate types.  Our  fourth  genus  is  composed  of  the 
remaining  portion  of  Ferussac's  HeliceUcs,  typically 
represented  by  those  disk-like  shells  which  are  destitute 
of  a  pillar ;  the  spire  very  short,  and  often  sunk  below  the 
level  of  the  margins  (as  in  Planorhis)  ;  the  body- whorl 
ventricose ;  and  the  outer  lip  considerably  thickened  : 
this  group  has  no  indications  whatever  of  the  incipient 
teeth  seen  in  Hemiodon,  and  yet  it  connects  the  land- 
volutes  and  the  present  sub-family  of  HelicincB  in  the 
most  perfect  manner.  We  shall  not  in  this  place  offer 
any  conjectures  regarding  the  fifth  type,  but  proceed 
at  once  to  give  our  analysis  of  the  two  typical  genera. 
Helix  and  Geotrochus,  so  far  as  it  has  yet  extended. 

(155.)  The  sub-genera  of  Helix  appear  to  us  to  be 
as  follows  :  —  The  first,  on  leaving  Hclicrlla,  is  Hemi- 
cychi,  distinguished  from  Helix  proper  by  the  broad  and 
flattened  margin  of  its  outer  lip,  and  by  the  absence  of 
the  inner,  except  occasionally  a  little  tubercle,  sufficient 
to  point  out  its   analogy  to  the   Lucernina' ;  but  there 

*  The  last,  or  body-whorl,  being  excluded. 


CHAP.   VI. 


SUB-GENERA    OF    HELIX,    ETC. 


165 


are  never  any  on  the  outer  lip.  In  the  second,  or  Helix 
proper,  the  spire  is  more  elevated,  the  shell  more  globose, 
the  umbilicus  covered,  and  the  outer  lip  more  or  less 
reflected  :  these  obviously  lead  to  Zonites,  which  chiefly 
differs  in  the  outer  lip  being  always  thin,  the  spire  more 
depressed,  and  the  umbilicus  more  or  less  open.  By 
degrees,  however,  the  spire  becomes  more 
and  more  elevated,  until,  in  that  sin- 
gular shell  Epistylia  conica*  {Jig.  18.  «), 
we  have  a.  Pupa  and  a  Helix  combined  in 
one  form.  The  last  is  a  very  beautiful 
type,  already  characterised  as  a  sub- 
genus by  Mr.  Gray,  under  the  appro- 
priate name  of  Strepsaxis,  while  its 
obvious  affinity  to  Hemicycla  brings  us 
again  to  the  point  whence  we  commenced, 
(156.)  The  genus  Geotrochus,  in  like  manner, 
seems  to  take  the  following  course,  corresponding  to 
that  of  Helix.  Vie  give  the  name  of 
Hemitrochus  to  certain  trochiform  shells, 
{jig.  1 9- )'  ^^^^^^S  ^^^  spire  nearly  as  elevated 
as  in  Epistylia,  but  less  thick  ;  the  whorls 
much  fewer,  and  the  inner  lip  margined 
internally ;  the  basal  whorl  is  not  angu- 
iated,  so  that,  if  the  spire  were  not  conic,  and  the  inner 
lip  not  thickened  within,  they  might  be  arranged  with 
Zonites.  These  shells  at  once  bring  us  to  the  typical 
sub-genus  Geotrochus '^xo^er,  where  the  body- whorl  in  its 
widest  circumference  is  more  or  less  carinated,  and  the 
spire  gradually  tapering  to  a  pointed  cone  ;  it  is,  in  fact, 
just  the  shape  seen  in  the  marine  Trochuses  :  in  some 
few  species,  chiefly  small  and  European,  the  margin 
of  the  lip  is  thin,  but  in  the  more  typical  ones  from 
tropical  America  it  is  thickened,  dilated,  and  almost  re- 
flected. Our  next  sub-genus,  Pithohelix  is  as  spiral  as  the 
last ;  the  spire,  however,  is  obtuse  at  the  top,  the  body 
whorl  not  angulated,  and  the  aperture,  consequently, 
rather  higher    than    broad :   such    as   have    the   spire 

*  Helix  epistyliiim  of  authors, 
M   3 


166 


SHELLS    AXD    SHELL-FISH. 


PART  I. 


more  than  usually  produced^  resemble  Bulimi,  but  with 
this  difference,  that  the  whorls  are  more  ventricose 
and  the  top  of  the  spire  more  obtuse ;  in  some  the 
base  of  the  pillar  forms  a  small  sinus  or  notch  before 
it  joins  the  thickened  outer  lip,  analogous  to  the  Acha- 
tince ;  but  in  that  the  margin  is  always  thin,  and 
the  spire  more  contracted  and  pointed  :  something  of  this 
form  belongs  to  our  next  sub-genus  Geomitra  {fig.  20.), 

founded  upon  a  most  extraordi- 
nary little  shell  discovered  by 
Mr.  Lowe  in  Madeira,  and  exhi- 
biting the  only  instance  of  coro- 
nated nodules  on  the  whorls  we  are  acquainted  with  in 
this  family.  The  form  is  that  of  the  last  type ;  but  the 
mouth  is  thin  and  completely  circular,  like  that  of  a 
Pupa,  to  which  genus  we  consider  it 
leads.  As  connecting  Geomitra  with  He- 
mitrochus,  we  here  place  the  fifth  sub- 
genus Gon}domus  (^fig.  21.),  which,  in 
the  distortion  of  its  whorls,  is  a  com- 
plete prototype  of  Strepsaxis.  The  ge- 
nera Helix  and  Geotrochus  would  thus 
appear  to  form  two  circles,  whose  sub- 
ordinate types  may  be  thus  stated. 


Analogies  of  the  Genera  Helix  and  Geotrochus. 

Analogical  Characters. 


Sub-genera  of 
Helix. 


Helix. 
Zoniles. 

Epistylia. 

Strepsaxis. 
Hemicycla. 


f  Body. whorl     large,    ventricose 
X     umbilicus  none. 


f  Body-whorl  depressed,  narrow  ;  ) 
\     umbilicus  open.  _> 

f  Spire    elevated,    oStuse  ;    body 
■s     whorl  depressed,  the  margi 
C     convex. 

Spire  and  whorls  distorted. 

f  Aperture  or  outer  lip  perfectly  > 
X     round.  J 


ns  > 


Sub-genera  of 
Geotrochus. 


Pithohelix. 
Geotrochus. 

Hemitrochus. 

Gonidomus. 
Geomitra. 


These  sub-genera  agree  sufficiently  well  to  render  any 
additional  illustration  unnecessary.     "\\^e  shall  therefore 


CHAP.    VI.  SUB-GENERA    OF    PUPA.  iGj 

at  once  proceed  to  the  genus  Pupa,  the  passage  to  which 
has  been  opened  by  Geomitra. 

(157.)  The  genus  Pupa  we  shall  restrict  to  those 
maggot-shaped  cylindrical  shells  whose  body- whorl  is 
larger  than  the  others,  whose  spire  is  thickened  in  the 
middle,  and  which  have  no  teeth  on  the  inner  lip  ;  the 
aperture  also,  in  three  out  of  the  five  sub-genera,  is 
always  round,  but  in  the  two  others  it  is  oval,  on  account 
of  their  blending  into  the  genus  ClausUia.  Having 
analysed  both  these  remarkable  genera,  we  feel  much 
more  confidence  in  stating  the  types  than  in  what  has 
been  said  regarding  those  of  Helix  and  Geotrochiis.  The 
type  of  this  present  group  is  that  extraordinary  and 
rare  shell  the  Megaspira  of  Lea,  of  which  a  noble  spe- 
cimen, containing  no  less  than  twenty-two  whorls,  is  in 
our  cabinet.  The  outer  lip  is  thin,  and  the  inner  want- 
ing ;  but  there  are  four  sharp  plates  close  together  at 
the  base  of  the  pillar,  and  a  central  one  on  the  inner  side 
of  the  body-whorl :  it  must  be  remarked  that  this  shell, 
although  of  such  excessive  length,  does  not  lose  the 
apex  of  its  spire,  which  is  obtuse  almost  to  its  very  tip : 
this  is  an  important  character,  because  it  is  carried  on 
to  our  sub-genus  Gonospira,  where  this  part  is  the 
same,  but  even  more  obtuse  :  the  volutions,  however, 
are  only  seven,  yet  the  shell  has  the  same  form  as  the 
last,  so  that  the  spiral  whorls  are  nearly  of  equal  thick- 
ness ;  the  aperture  is  more  that  of  Pupa,  being  oval ;  it 
is  thickened  all  round,  and  there  is  a  tooth  at  the  upper 
angles.  This  leads  at  once  to  the  sub-genus  of  Pupa 
proper,  distinguished  from  both  the  foregoing  by  the 
suddenly-pointed  shape  of  the  apex,  and  the  increased 
thickness  of  the  two  lips^  which,  as  in  Gonospira,  are 
united :  all  the  typical  species  in  like  manner  have  a 
tooth  ;  but  this  disappears  in  such  species  as  pass  into 
Plicadomus ,  where  the  inner  lip  is  entirely  wanting,  the 
aperture  having  a  dilated  margin,  and  perfectly  entire, 
while  the  apex  of  the  spire,  no  longer  suddenly  con- 
tracted, is  obtuse  :  it  is  by  this  sub-genus,  as  we  think, 
that  the  whole  group  is  united  to  Geomitra  ;  and  it  may 

M  4 


}68 


SHELLS    AND    SHELL-FISH. 


PART  1. 


be  observed,  that  in  the  strongly  sculptured  ridges  of 
most  of  the  species,  a  nearer  approach  is  made  to  the 
coronated  Geomitra  {fig,  20.),  than  to  any  other  land 
shell.  The  last  sub-genus  to  be  noticed  was  long 
ago  characterised  by  the  masterly  pen  and  pencil  of 
Guilding,  but  seemingly  overlooked  by  our  concholo- 
gists  ;  it  is  his  Siphonostotna  *,  and  is  distinguished  at 
once  both  by  the  animal  and  its  shell  (S.  cosfata  Guild., 
fig.  22.).     The   foot    is    remarkably   short,    while    the 

spire  of  the  shell   is  deci- 


duous, i.  e.  falling  off  soon 
after  it  has  reached  matu- 
rity ;  sometimes,  indeed,  the 
animal  has  been  captured 
before  this  process  takes 
place  :  the  shell  is  then  re- 
markably beautiful,  exhibiting  as  many  whorls  as  3/rtcro- 
spira,  but  with  this  difference,  that  the  upper  portion  is 
gradually  attenuated  to  a  fine  point :  this  type  is  thus 
separated  from  Macrospira,  not  only  by  its  decidu- 
ous spire,  but  by  its  round  aperture  and  its  thickened 
lips,  which  gives  it  all  the  aspect  of  a  Cgclostoma, 
except  that  the  margin  of  the  lips,  in  some  species,  is 
even  detached  from  the  body-whorl.  That  there  will 
be  intervening  modifications  between  each  of  these  sub- 
genera,  so  that  they  may  be  blended  more  harmoniously 
together,  can  admit  of  little  doubt :  our  only  regret  is, 
at  present,  that  they  are  too  strongly  marked  and  dis- 
tinct ;  nevertheless,  we  may  feel  confident,  after  studying 
the  annexed  table,  that  these  forms  follow  each  other  in 
the  order  in  which  they  are  now  placed.  We  insert  in 
this  place  the  series  of  the  ClausilicB,  which  represent 
Fiipa,  in  order  to  show  the  intimate  relations  of  the 
two  groups ;  but  we  shall  subsequently  return  to  that 
genus,  because  it  forms  part  of  the  sub-fiimily  Acha- 
tince. 


*  Guilding  imposed  this  name  after  he  bad  discovered  ihat  Brachipits 
had  been  used  by  us  to  designate  a  group  of  birds. 


CHAP.   VI.  ANALOGIES    OF    PUPA.  16Q 

Analogies  of  the  Genera  Pupa  and  Clausilia. 

Sub-genera  Sub-genera         Genera 

of  Analogical  Characters.  of  of  the 

Pupa.  Clausilia.       Helicin-e. 

r Sub-typical;  whorls  nume-^ 
Megasplra.       ^     rous,  all  persistent ;  \ivab'\->Balea.  Helix. 

t.     Heated.  j 

r Typical;  spire  deciduous;'! 
Si'pkonostoma .  <     lips  generally  detached  from  >  Clausilia.        Geotrochus. 

C     the  body-whorl.  J 

r  Outer  lip  with  the  n:argin,  ^ 
Plicadomus.     \     considerably    dilated,    and  ^  Macrodontes.  Pupa, 

C     the  edge  reflected.  j 

Pupa.  [^Sr'?''''   ^'^^   """"'^'""'jp^pf/to.  ? 

Gonospira.        pP'reo^t^few  whorls,  and  very  j  ,  Helicella. 

The  resemblances  between  the  sub-genera  of  Pupa 
and  those  of  Clausilia  are  too  obvious  to  be  dwelt 
upon  ;  but  those  between  the  first  column  and  the  last 
require  some  explanation.  The  spire  of  Helix  is  al- 
ways obtuse^  so  is  that  of  Megaspira  ;  in  Geotrochus 
and  Siphonostoma,  on  the  contrary,  the  terminal  por- 
tion of  the  whorls  is  acutely  conic  ;  and  this  form  is 
carried  to  such  an  extent  in  the  deciduous  portion  of 
some  species^  that  they  actually  put  on  the  appearance 
of  being  long-spired  trochiform  shells,  instead  of  a 
portion  only  of  that  to  which  they  really  belong.  He- 
licella and  Gonospira  agree  in  the  paucity  of  their 
whorls;  while  the  fifth  type,  w^hich  should  represent 
Pupa,  has  not  been  determined.  If  we  wished  to  carry 
our  analogies  into  the  zoophagous  tribes,  it  is  clear  that 
the  strombiform  type  is  the  third,  and  the  volutiform 
the  fifth,  of  the  above  series. 

(158.)  We  feel  unprepared  to  offer  any  definite  opi- 
nion on  the  extent  or  the  subordinate  types  of  the  genus 
Helicella  ;  it  stands  at  the  confines  of  the  Helicin^  and 
the  LucERNiN^,  and  therefore  may  be  supposed  to  par- 
take in  the  characters  of  both.  We  even  think  that 
several  of  the  perfectly  discoid  shells,  now  arranged 
with  Cyclostoma,  such  as  Cy.  planorbula*,  will  event- 

*  Ency.  Meth.  431.  fig.  3. 


170 


SHELLS    AND    SHELL-FISH. 


PART  I. 


ually  prove  the  real  types  of  this  group^  which  repre- 
sents Cyclostoma  among  the  Helicin-s;. 

(159.)  The  AcHATiN^,  as  we  have  already  shown, 
constitute  the  sub-typical  group,  representing  in  their 
own  family  the  zoophagous  tribe.  This  analogy  is  seen 
in  two  ways  :  first,  they  are  the  most  spiral  of  all  the 
Helicidce,  just  as  the  Zoophaga  are  the  most  spiral  of 
all  the  Testacea  ;  secondly,  they  are  the  only  ones  where 
the  indication  of  a  basal  channel  is  seen,  as  if  to  pre- 
pare us  for  the  full  development  of  that  character  in  the 
next  great  tribe  which  succeeds  this.  But  setting  aside 
all  these  considerations,  at  least  for  the  present,  we  will 
at  once  proceed  to  characterise  the  five  genera  into 
which  they  appear  to  divide  themselves.  1.  In  Achatina, 
properly  so  called  (^A.marginata^^w.Jig.  23.),  the  basal 

extremity  of  the  pillar  is  trun- 
cated, so  as  to  present  a  distinct 
separation  between  it  and  the 
outer  lip ;  this  lip  also  is  always 
thin  and  sharp-edged  at  every 
period  of  age.  2.  In  BuUmus, 
on  the  contrary,  the  outer  lip 
is  more  or  less  thickened  and 
reflected  backward ;  while  the 
inner  lip  —  always  absent  in 
Achatina  —  forms  either  a  little 
fold  just  below  or  near  to  the 
umbilicus,  or  is  continued  up, 
and  spreads  a  polish  over  the 
left  side  of  the  aperture  :  the  general  shape  of  the  shell 
in  the  typical  sub-genera  of  both  this  and  the  last  is 
obovate,  having  the  body-whorl  much  the  largest,  and  the 
aperture  without  teeth,  except  in  the  sub-genus  Auri- 
cula. This  leads  to  the  next  or  8d  genus,  Clausilia :  in 
these  the  spire  is  excessively  long  in  proportion  to  the 
aperture,  the  basal  or  body-whorl  being  hardly  larger  than 
the  others  ;  and  the  aperture,  moreover,  is  furnished 
with  various  folds,  or  toothlike  process.  The  ^th, 
Helicina  {Jig.  18.  b),  is  distinguished  at  first  sight  by  its 


CHAP.   VI.        THE    SUB-GENERA    OF    ACHATINA.  171 

rather  depressed  form,  but  still  more  by  its  semicircular 
aperture,  always  closed  by  a  horny  operculum :  the  typical 
species  are  also  peculiar  from  having  a  narrow  notch, 
or  rather  slit,  at  the  base  of  the  outer  lip.  The  5th 
and  last  genus  is  Cyclostoma,  distinguished  by  its  mouth 
and  operculum  being  perfectly  circular ;  the  margin  of 
the  lip  is  also  more  or  less  dilated  into  a  fringe  or 
thickened  rim.  We  shall  now  take  each  of  these  genera, 
and  describe  what  appear  to  us  the  types  of  form  or 
sub-genera  in  each. 

(160.)  The  first  and  typical  genus,  Achatina  Z<am., 
includes  the  largest  sized  shells  of  all  those  inhabiting 
the  land  :  they  are  chiefly  found  in  Africa,  where  the 
natives  use  them  as  food,  and  expose  them  for  sale  in 
the  markets.  The  inside  of  the  mouth  is  sometimes  of 
a  brilliant  rose-colour,  and  the  outsides  of  nearly  all  are 
elegantly  marbled  with  white  ;  but,  as  the  epidermis  is 
very  tenacious,  the  ground  colour  appears  olive.  The 
body-whorl  of  these  typical  species  is  large  and  ventri- 
cose,  the  outer  lip  simple,  and  the  whole  shell  solid : 
but  in  the  next  type,  or  Cochlicopa  of  Ferussac*,  the 
body-whorl  is  more  slender  and  cylindrical,  and  the 
shell  is  placed  very  much  towards  the  end  of  the  disk 
or  foot  of  the  animal,  which  makes  this  part  appear  very 
short :  by  degrees,  however,  the  spire  becomes  length- 
ened, and  the  body- whorl  proportionably  smaller  ;  and 
in  these  aberrant  species,  nearly  all  of  which  are  longi- 
tudinally striated,  the  margin  of  the  outer  lip  is  more 
sinuated.  This  elongation  of  the  spire  prepares  us  for 
the  sub-genus  Macrospira  Guild,,  where  the  spire 
becomes  excessively  long  and  cylindrical  ;  yet  the  lip  is 
still  very  thin,  and  the  pillar  is  truncated,  or  notched  at 
the  base,  precisely  as  in  all  the  other  types.  In  one  or 
two  species  we  observe,  for  the  first  time,  a  thickened 
fold  in  the  middle  of  the  pillar,  analogous  to  what  is 
seen  in  some  of  the  Auriculce  and   the  Pupce,     Now, 

*  We  adopt  M.  Fenissac's  names  whenever  they  have  a  right  of  priority 
and  are  classical ;  this  group  has  been  called  by  the  strange  appellation  of 
Polyphemus,  as  if  the  animal  had  not  two  eyes,  but  one  only  ! 


172  SHELLS    AND    SHELL-FISH.  PART  I. 

this  same  thickening  of  the  pillar  into  a  central  fold  is 
observable  in  Leucoatoma,  —  a  name  by  which  we  now 
designate  a  remarkable  little  shell  (^fig.  24.)  of  the 
^  same  shape  as  the  more  elongated 
AchatinellcEy  but  with  the  addition 
of  a  thick  gibbous  mass  of  white 
enamel  placed  on  the  top  of  the 
aperture  within,  where  the  outer 
lip  joins  the  body-whorl :  this 
little  pad,  in  short,  is  exactly  the  same  as  what  is  seen 
in  Melanopds,  —  the  base  is  distinctly  emarginate,  and 
the  outer  lip  thin  ;  but  then  the  substance  is  more 
like  that  of  a  marine  than  a  land  shell,  and  both  the 
interior  of  the  aperture,  and  the  outside  of  the  whorls, 
are  transversely  striated  :  the  space  between  the  upper 
pad  and  the  commencement  of  the  plait  on  the  pillar 
is  without;  enamel,  and  is  so  short  that  it  has  the  ap- 
pearance of  a  deep  notch  :  that  this  shell,  hoAvever, 
either  by  affinity  or  analogy,  has  a  strong  relation  to 
the  types  where  we  now  place  it,  admits  of  little  doubt ; 
our  difficulty  lies  in  determining  bet%veen  these  two 
relations.  If  not  a  marine,  it  may  be  an  amphibious 
species  ;  in  this  respect  it  seems  to  have  a  relation  of 
analogy  to  Melanopsis,  as  well  as  one,  more  near,  to 
PlancLvis.  Achatenilla  is  our  fifth  and  last  type.  These 
little  shells  are  remarkable  for  the  beauty  of  their  colours; 
they  are  all  inhabitants  of  the  Pacific  Islands,  where 
they  are  used  as  bead-like  ornaments.  They  are  at 
once  known  by  the  thickened  rim  on  the  internal  part  of 
the  outer  lip  :  were  this  rim  external,  nothing  but  the 
truncated  pillar  would  prevent  these  shells  being  placed 
with  the  CyclostomcB.  With.  Achatinella,  in  fact,  the 
circle  is  closed.  Its  connection  to  Achatina  proper,  with 
which  our  survey  began,  is  effected  by  that  well-known 
shell,  the  A.  viryinea,  which  is  almost  an  aberrant 
Achatinella  :  in  this  well-known  species,  the  aperture 
is  very  oblique,  as  in  Achatinella  pica,  and  the  pillar, 
like  that  shell,  considerably  turned  inward.  The  thick- 
ening  on    the  inner  margin    of   the  outer  lip   is   not 


CHAP.   VI. 


ANALOGIES    OF    THE    ACHATIN.E. 


173 


observed  in  young  shells ;  and  even  in  those  which 
are  adult  it  is  very  slight^  yet  it  is  distinguishable. 
In  the  typical  Achatina,  on  the  contrary^  the  base  of 
the  pillar  is  turned  outwards^  the  mouth  is  not  ob- 
lique, and  the  whole  of  the  outer  lip  is  so  thin  and 
fragile,  that  it  breaks  on  the  slightest  touch  :  a  more 
intimate  union,  in  short,  cannot  possibly  exist. 

(161.)  Having  now,  to  all  appearance,  closed  the 
circle  of  Achatina,  we  may  compare  it  with  the  primary 
divisions  or  genera  of  this  sub-family. 


Analogies  of  the  suh-genera  o/'Achatina. 


Sub-genera. 
Achatina. 
Cochlicopa. 

Macrospira. 

Leucostoma  ?. 
Achatinella. 


Analofiical  Characters. 

f  Large  ;  ventricose  ;  strictly  typi- 
l      cal. 

fBodV-whorl     more     contracted 
X     spire  more  lengthened. 

"Shell    cylindric  ;     spire     exces- 
sively   long ;    the    body-vhor 
small ;    aperture  short,  nearly 
round. 
rOuter  lip  with  a  distinct  notch  at 
^     the  base;  inner  lip  not  thick- 
C     ened  internally. 
f  Lip  thickened  ;  aperture  nearly  7 
\     round.  3 


] 
J 

1 


Genera  of  the 
AchatintB. 

Achatina. 

BULIMUS. 

Clausiua. 

Helicina. 
Cyclostoma. 


This  result  of  following  the  course  of  affinities  is  im- 
portant, as  showing  that  the  modifications  of  the  spiral 
snails  are  regulated  on  a  uniform  and  a  very  simple 
system.  The  more  experienced  zoologist  need  hardly  be 
reminded,  that,  in  comparing  Cochlicopa  with  Bulimus, 
we  institute  the  comparison  with  that  division  of  the 
latter  genus  which  is  sub-typical,  because  Cochlicopa 
is  also  sub-typical  :  in  both  these  the  spire  is  as  long, 
and  generally  longer,  than  the  body-whorl ;  whereas  in 
the  pre-eminently  typical  Achatmce  and  Bulimi,  the 
body-whorl  is  ventricose,  and  the  four  whorls  of  the  sVue 
short.  So  beautifully  do  the  greater  part  of  these  xive 
sub-genera  of  Achatina  blend  and  pass  into  each  other, 
that  it  is  no  easy  matter  to  detemiine  where  one   ends 


174  SHELLS    AND    SHELL-FISH.  PART  I. 

and  the  other  begins.  Leucostoma,  however,  is  an 
exception  ;  it  is  more  isolated,  and  consequently  its  pre- 
sent position  is  very  doubtful.  There  is  also  a  hiatus 
between  Leucostoma  and  Achatinella;  but  then  this  last 
is  so  perfectly  connected  to  Achatina,  that  nothing  can 
separate  them.  Thus  we  have  four  lifths  of  a  circle  ab- 
solutely perfect;  so  that,  if  Leucostoma  had  been  undis- 
covered, and  the  fifth  type  entirely  wanting,  still  this 
deficiency  would  not  affect  the  general  principles  of  our 
arrangement, — we  should  still  have  four  of  the  sub- 
genera intimately  representing  four  of  the  genera  ;  and 
we  should  conclude,  by  inductive  reasoning,  that  the 
fifth  of  the  former,  when  discovered,  would  represent 
the  fifth  of  the  latter. 

(l6i}.)  The  most  numerous  in  species,  and  hence 
the  most  varied  in  their  forms,  of  all  these  sub-genera, 
is  that  of  Achatina  proper.  In  consequence  of  this  va- 
riation, the  species,  as  is  usual,  assume  the  forms  of 
the  genera  and  families  which  surround  them  ;  so  that 
they  might  be  called  sectional  types.  An  instance  of  this 
we  have  already  shown  in  Achatina  virginea,  which,  with 
its  allies,  obviously  represents  Achatinella  ;  then  comes 
Achatina  Zebra,,  &c.  as  the  pre-eminent  types  of  all  : 
following  this,  we  have  such  shells  as  A.  elongata  Sw.* 
&c.,  with  their  longer  spire,  and  thus  assuming  one  of 
the  chief  characters  of  Cochlicopa  ;  while  A.  crenata  t, 
and  perversa  j,  &c.,  by  their  still  more  produced 
spire,  immediately  remind  us  of  Macrospira  :  the  de- 
pressed form  of  Ach.  Sultana  ^  finds  its  prototype  in  the 
unusually  depressed  Helicince ;  and  thus  we  have,  in 
this  single  sub-genus,  indications  of  all  the  genera  of 
the  sub-family.  This  is  sufficient  to  show  the  neces- 
sity of  rigid  analysis,  before  we  can  determine  what  is 
the  rank  of  a  particular  division,  whether  it  be  sec- 
tional, sub-generic,  or  even  generic  :  the  same  may  be 
said  of  higher  assemblages ;  for  it  is  impossible  to  know, 
a  priori,  what  groups  are  of  the  rank  of  sub-families  or 

*  Chem.  pi.  11!».  f  1124, 1125.         f  Zool.  Illustrations,  1st  Series. 
J  Exotic  Conch. 


CHAP.   VI. 


ANALOGIES    OF    THE    ACHATINiE. 


175 


families^  before  the  whole  tribe  has  undergone  a  careful 
examination. 

(163.)  The  foregoing  series,  constituting  the  sec- 
tional types  of  our  sub-genus  Achatina,  will  be  ren- 
dered more  plain  to  the  general  reader,  if  thrown  into 
a  table  in  the  following  manner :  — 


Analogies  of  the  Species  in  the  Sub-genus  Achatina, 


Sectional 
Division  of 
the  Species, 

A.  Zebra. 


A.  elongata. 

A.  perversa. 
A.  Sultana. 
A.  virginea. 


Analogical  Characters. 


Sub-genera       Genera 
of  of  the 

Achatina.    Achatina. 


'X 


dchatina.       Achatina. 


BULIMUS. 


r  Ovate;      ventricose;      spire 

<  short  ;     outer    lip    simple 
L     not  binuated. 

rOvale;    aperture  nearly    or 

<  quite  entire;    spire  more  ^Cochlicopa 
t     lengthened.  j 

f  Spire  lengthened  and  attenu-  }  ^acrn-imra 
\     ated;  body. whorl  short.      ^  ^^^acrospira. 

f  Spire  rather  depressed;  base  >  r  v         s  tt„ 

\     deeply  notched.  jie«co5^ow«.?  Helicina. 

C  Aperture  nearly  round;   lip  ^  <  7    ,.    „       ^ 

I     margined.  j  ^chatmella.    C\clostoma. 


Clausilia. 


Now,  this  is  the  smallest  group  which  can  be  made 
out,  next  to  the  actual  species  which  come  under  each 
section  ;  and  yet  every  conchologist  who  possesses  an 
extensive  series  of  these  shells,  or  even  of  those  we  have 
named,  must  perceive  that  no  other  divisions,  or  sec- 
tions, can  be  formed  with  any  degree  of  propriety  ,•  that 
is  to  say,  if  he  were  asked  to  single  out  the  most  diver- 
sified forms  from  the  sub-genus  Achatina,  the  above  are 
those  he  would  probably  fix  upon.  Now,  this  series, 
small  as  it  is,  turns  out  to  have  a  circular  succession  ; 
and  not  only  that,  but  likewise  to  represent  all  the 
sub-genera  and  genera  of  the  family.  Hence  it  would 
seem  that  the  essential  character  of  this  sub-genus  is  to 
have  the  contour  of  the  aperture  simple  —  not  sinuated 
or  dilated,  as  in  the  next  sub-genus,  Cochlicopa.  The 
Cochlicopa  maculata  thus  seems  to  be  neither  an  Achatina, 
nor  a  distinct  sub-genus,  as  some  have  imagined,  for  we 
do  not  believe  it  is  a  marine  mollusk. 

(164.)  The   preceding    analysis   of  Achatina    inci- 


176 


SHELLS    AND    SHELL-FISH.  PART   I. 


dentally  explains  the  essential  characters  of  Cochlicopa. 
Quoy  and  Gaimard  have  figured  the  animal  of  the  last 
sub-genus,  and  M.  Ferussac  of  this,  which  is  distin-. 
guished  by  the  very  backward  position  of  the  shell  ;  but 
the  typical  form  of  Cochlicopa  appears  to  be  oblong 
ovate,  the  spire  and  aperture  nearly  equal,  the  whole 
shell  distinctly  striated  longitudinally,  and  the  outer  lip 
forming  a  sinuated  curve  near  its  base  ;  the  substance  is 
almost  always  very  thin  ;  and  the  colour  is  light  fawn, 
never  marbled  or  banded  transversely,  but  sometimes 
longitudinally :  those  species  which  pass  into  Macro- 
spira  have  such  a  long  spire,  that,  but  for  the  oval 
aperture  and  regular  strife,  they  would  not  be  known. 
The  species  appear  confined  to  the  tropical  latitudes  of 
the  Old  and  the  New  World.  On  the  remaining  sub- 
genera, viz.  Macrosjnra  Guild.,  Leucostoma,  and  Acha- 
tinella,  nothing  more  can  here  be  said. 

(16.5.)  The  next  genus,  Bulimus,  is  a  most  exten- 
sive and  varied  one.  It  represents  the  typical  Helices, 
or  snails ;  and  has,  consequently,  the  aperture  perfectly 
entire,  the  end  of  the  pillar  being  blended  with  the 
outer  lip  :  except  in  one  of  the  sub-genera.  Auricula, 
the  pillar  has  neither  teeth,  folds,  nor  plaits  ;  and  even 
in  this  solitary  group,  the  largeness  of  the  body-whorl, 
the  shortness  of  the  spire,  and  the  thickened  margin  of 
the  outer  lip,  are  all  certain  indications  of  its  belonging 
to  the  genus  Bulimus.  The  Bulimi,  in  fact,  possess 
all  the  characters  of  the  genuine  Auriculcp,  but  without 
their  folds.  There  is  no  perceptible  difference  in  the 
animals  of  the  two  typical  sub-genera ;  and  that  of  two 
of  the  others  are  unknown. 

(166.)  We  shall  connnence  the  survey  of  this  ex- 
tensive group  at  that  point  where  it  joins  Achatina. 
This  union  is  effected  by  our  new  sub-genus  Lepto- 
spira, which,  as  its  name  implies,  has  the  spire  exces- 
sively long  and  slender ;  their  form,  in  fact,  is  precisely 
like  that  of  the  Macrospira,  but  the  aperture  is  entire, 
and  the  outer  lip  thickened.  A  remarkable  shell  in  our 
cabinet,  once  the  property  of  the  duchess  of  Portland, 


CHAP.   VI.  HELICID^.  BULIMUS.  177 

exhibits  the  typical  perfection  of  this  form  :  but  there 
are  others,  much  smaller,  where  the  outer  lip  is  thin  ; 
and  these  are  the  connecting  links  between  this  and 
Macrospira.  The  well-known  Helix  decollatus  Linn, 
seems  to  belong  to  this  sub-genus,  and  conducts  us  im- 
mediately to  Biilimiilus  of  Leach.  We  now  come  to 
shells  of  the  ordinary  shape  ;  the  outer  lip  is  rather  thin 
or  scarcely  reflected,  and  the  inner  so  little  developed 
that  it  merely  forms  a  thin  plate  over  the  umbilicus, 
where  this  latter  exists.  Before  we  had  sufficiently 
analysed  this  family,  we  were  little  disposed  to  adopt 
this  sub-genus.  Its  characters  are  so  very  slight,  and 
the  greater  or  lesser  reflection  of  the  outer  lip  is  so 
variable,  that  we  did  not  think  such  considerations  alone 
were  sufficient  to  authorise  the  separation  of  these  shells 
from  Bulimiis:  more  particularly  as  the  exquisite  draw- 
ings of  Guilding  did  not  show  any  outward  difl?erence  in 
their  animals.  But  no  sooner  had  it  become  evident  to 
us  that  BuUmulus,  in  fact,  was  the  representative  not 
only  of  Zonites,  but  of  Achatina,  than  the  full  value  of 
the  distinction  became  manifest.  There  are  not  many 
sectional  forms  among  these  shells,  which  are  all  rather 
of  a  small  size;  but  some,  as  the  BuUmulus  undulatus, 
Antiguensis,  and  Proteus  Guild.,  are  very  elegant.  The 
third  sub-genus,  or  Bulimus  proper,  is  a  very  numerous 
one.  The  fact  is,  that,  being  the  pre-eminent  type  of 
all  these  sub-genera,  it  contains  representations  of  all, 
and  under  more  modifications  than  are  found  in  Acha- 
tina proper.  As  we  shall  return  to  these 
shells  subsequently,  we  may  now  pass 
on  to  Auricula,  the  fourth  sub-genus, 
which,  with  the  general  form  of  Buli- 
mus, although  less  ventricose,  unites  the 
peculiar  character  of  having  one,  or 
sometimes  two,  plaits  on  the  pillar  near 
the  base  of  the  aperture.  The  next 
genus,  hitherto  overlooked,  is  Gonyo- 
stonia  {fig.  25.),  represented  by  the  Bu- 
limus of  that  name.     The  length  of  its  spire,  and  the 

*  N 


178 


SHELLS    AND    SHELL-FISH. 


PART  I. 


distorted  aspect  of  its  mouthy  —  although  quite  unique 
in  this  group,  —  are  not  its  only  characters;  for  at  the 
base  of  the  aperture  is  a  little  emargination  or  notch, 
analogous  to  what  is  seen  in  Helicina,  Leucostoma,  and 
Anastoma.  By  the  length  of  its  spire,  it  evinces  such 
an  affinity  to  Leptospb'a,  that  we  insensibly  find  we  have 
returned  to  the  group  we  commenced  with.  The  sub- 
genera of  Biilimus  thus  form  a  circle,  without  the  absence 
of  a  single  link  in  the  chain  of  continuity. 

(167.)  The  sub-genera  Bulimus  and  Auricula  are 
the  only  two  which  will  require  further  illustration. 
The  first,  from  being  pre-eminently  typical,  contains, 
Vike  Achatina,  sectional  types,  representing  the  five  prin- 
cipal forms  in  this  family.  The  Bulimus  hcBmastomus 
(Jig. '2,6.)  is  the  chief  of  these,  and  is  an  exact  counterpart 

of  the  Achatina  ])erdijc  Lam.  of 
the  opposite  circle.  It  is  a 
large  ventricose  shell,  with  a 
spire  much  shorter  than  the 
body-whorl,  and  of  only  four 
volutions.  In  the  next  type, 
Bulimus  interruptus*  of  La- 
marck, these  proportions  are 
not  preserved ;  the  form  is 
more  slender,  the  body-whorl 
less  ventricose,  the  spire  more 
lengthened,  and  the  whole  aspect 
reminds  us  of  Achatina  regi- 
na  t  and  its  allies.  These  are  followed  by  such  shells  as 
Bui.  /M7>;-icM.9  Lam.,  having  very  much  the  cylindrical  form 
of  Pupa;  the  outer  lip  is  nearly  round,  but  there  is  no 
inner  lip,  or  any  tooth  in  the  pillar.  In  the  third  mo- 
dification we  see  a  complete  prototype  of  the  sub-genus 
Goniostoma,  in  that  singular  shell  the  Bulimus  Lyonc- 
tianus,  where  the  aperture  protrudes  on  one  side,  and 
appears  distorted.  Last  of  all  comes  those  small  Pa- 
cific species  (mistakingly  separated  as  a  genus,  under 


Chemnitz,  pi.  101.  fig.  938,  939. 


+  Zool.  111.  1st  Series. 


CHAP.   VI.       TYPES    OP    THE    SUB-GENUS    BULIMUS.        179 

the  name  of  Partula),  where  the  margin  of  the  aperture^ 
instead  of  being  completely  reflected^  as  in  all  the  other 
types,  is  only  very  much  dilated  or  spread  out.  This 
peculiar  character  brings  us,  of  course,  to  the  confines 
of  the  sub-genus  Bulimulus ;  and  by  such  shells  as  the 
Bulimus  melanostomus  of  Brazil  (which  will  completely 
answer  to  the  characters  given  of  Partula*)  we  return 
again  to  B.  hcemastomus.  By  arranging  these  species 
in  a  column,  as  sectional  divisions,  they  will  be  found 
to  represent  the  primary  types  of  the  spiral  land  shells 
in  the  following  manner :  — 


Analogies  of  the  Sectional  Types  of  the  Sub-genus  Bu- 
limus. 


Genera 

of  the 
Achat  ince. 


Bulimus, 


ACHATINA. 


Sectional 
Types  or  Species. 


Analogical 
Characters. 


Sub-genera 
of  the 
Bulimi. 


f  Shell  vontricose;^ 
I      spire      short  ;  ) 
Hamastomus.  <;     aperture  in  the  |>  Bulimus. 
I      typical   species  ] 
[_    always  rosy.      J 


Interiuptus 
Lara. 


Clausilia.       Lubricus. 


Helicina.        Lyotietianus. 


Ctclostoma.  Australis. 


Shell  more  slen 
der;  spire  e 
vated. 


;n-l 

le-  >  Bulimulus. 


fSpire  lengthened;"! 
I     basal    volution  J 
■{     smaller  or  very  )■  Leptospira. 
I      little         larger  | 
L    than  the  next.  J 

r  Aperture  distort 
3  ed,  with  a  dis- 
i  tincl  notch  at 
t     the  base. 


\ 


Sub-genera 

of  the 
AchatincE. 


ACHATINA. 


COCHLICOPA. 


Macrospira 


GONIOSTOMA.    LeUCOSTOMA  ? 


fOuter  lip  thick-1 

I     enedmoretlian  J 

\      usual;  a  slight  i. 

1     fold  on  the  pil-  J" auricula. 

I      lar;     aperture  I 
L    ear-shaped.       J 


ACHATINELLA. 


*  "  Partula.  Conical,  smooth,  spire  equal  to  aperture  in  length,  con- 
sisting of  few  whorls;  aperture  auriform  ;  outer  lip  reflected,  broad  ;  inner 
lip  reflected,  with  a  slight  prominence  on  the  columella." — iSoiverbt/'s  Ma- 
nual, p.  77.  if  the  student  turn  to  the  figure  of  B.  melanosto/nus  Zool.  111. 
1st  Series,  he  will  find  this  description  perfectly  applicable  ;  yet  this  latter 
has  been  arranged  as  a  Bulimus,  and  placed  in  a  different  family. 

N    2 


180  SHELLS    AND    SHELL-FISH.  PART  I. 

The  variations  in  the  forms  of  the  species  are  thus  seen 
to  be  a  primary  character  in  all  these  groups^  whether 
we  look  to  the  primary  divisions  or  genera^  or  to  their 
sub-genera.  It  is  singular  how  very  closely  some  of 
the  little  shells  of  Ferussac's  Partula  put  on^  as  it  Avere, 
the  very  colours  of  the  Achatinellce,  which  they  are  to 
represent ;  and  even  the  "  slight  prominence  on  the 
columella"  is  analogous  to  the  thickened  fold-like  ter- 
mination of  that  part  in  some  Aohatince:  both^  more- 
over, are  chiefly  found  in  the  Pacific  islands ;  and  both, 
by  having  the  broadest  lips  of  their  respective  congeners, 
aptly  represent  the  Cyclostomce. 

(168.)  The  sub-genus  Auricula  is  no  less  interesting 
than  the  last ;  because,  although  few  in  species,  its  re- 
lations are  unusually  complicated.  We  shall  first  notice 
those  types  upon  which  there  can  be  few  or  no  doubts, 
and  then  advert  to  such  as  are  questionable.  The  know- 
ledge which  Guilding's  drawings  of  the  Auricula  un- 
dulata*  has  given  us  of  the  animal,  clearly  shows  its 
close  approximation  to  that  of  Bulimus  hcemastomus,  also 
figured  by  the  same  exquisite  artist.  This  fact  goes  to  es- 
tablish Auricula  as  a  division  of  the Bulimi,  and  we  have 
to  consider  what  other  shells  showaclose  similarity  to  this. 
The  species  we  may  thus  select,  are  the  Auricula  Dombey- 
ana,  Auris-Leporis,  Sileni,  and  JBovina  ;  and  the  whole 
group  may  be  described  as  shells  with  the  aperture  rather 
larger  than  the  spire,  the  whorls  of  the  latter  few  and 
produced,  the  pillar  one  or  two  plaited,  and  the  outer 
lip  (except  in  Dombeyana  +)  thickened  and  reflected  on 
he  external  edge.  This  latter  definition  would  exclude 
Auricula  midce,  and  those  other  dubious  terrestrial  spe- 
cies whose  spire,  although  much  shorter,  is  composed  of 
more  whorls.  We  suspect,  indeed,  that  these  latter  shells 
are  nearly  allied  (through  Pedipes  and  Melampus^  to 
Tournatella  ;  in  which  case  both  them  and  the  sub-genus 
Scarabus  must  be  removed  from  the  Helicidce,  a.i\d  placed 

*  Plecocheilus  iinilulatiis  Guikling,  Zool.  111.   Cd  Series,  pi.  10'3. 
t  I  apprelierui,  however,  that  in  perfectly  adult  specimens,  this  species 
has  a  similar  outer  lip  to  A.  Silent. 


CHAP.  VI. 


AURICULA. 


BULIMUS. 


181 


with  the  Turbidw.  Certain  it  is,  that  these  animals  (made 
known  by  the  excellent  figures  of  the  French  voyagers) 
are  very  diiFerent  from  the  Auricula  undulata;  they  have 
only  two  short  and  depressed  tentacula  with  basal  eyes, 
as  in  Pedipes*,  instead  of  the  usual  structure  of  these 
organs  common  alike  to  Auricula  undulata  and  Bulimtis 
hcemastomus.  On  these  reasons  do  we  restrict  the  sub- 
genus Auricula  to  the  characters  above 
stated  —  at  least,  until  further  inform- 
ation leads  to  a  different  conclusion.  Of 
aU  the  species  of  Auricula  here  named, 
the  Auris-Leporis  (fig.  27.)  is  the  most 
remarkable ;  the  plait  on  the  pillar  is  not 
real,  inasmuch  as  it  is  not  solid,  but 
formed  by  a  sharp  angle  of  the  body- 
whorl  round  the  umbilicus;  the  aperture 
is  large,  and  so  oblique  as  to  appear  dis- 
torted. It  is  by  this  shell  that  we  pass  to  the  sub- 
genus Goniostoma  already  mentioned  (fig.  25.).  The 
five  sub-genera  of  Bulimus  will  thus  form  a  circle,  and 
present  us  with  the  following  analogies  :  — 


Analogies  of  the  Sub-Genera  o/'Bultmus. 


Genera         Sub-genera 
of  the  of 

Turbidte.  Bulimus. 


Analogical 
Characters. 


Genera 

of 

AchatincE, 


Turbo. 


Bulimus 


'Body-whorl  large,' 

itricose;  spire  J-BuuMUS. 


f  Body- 
•<  vent 
L     shor 


TuRRiTELLA.    Bulimulus 


ScALARiA.        Leptospi 


hort.         "    "       5 
Body,  whorl   more  "J 
slender;  outer  lip  f  a  p„,T,,„. 
thin,      or     veryf'^'^"^^"^^- 
slightlyreflected.  J 
f  Spire     excessively  T 
ira.  <     long:  body-whorl  J- Clausilia. 


Sub-genera 

of 
AchatiniS. 

Achatiniz. 


CochUcopa. 


Macrospira. 


ScissuRELLA.   Goiiyostoma 


Melampus.      Auricula. 


Helicina. 


Leucostoma  ? 


small.  J 

A  slight  notch  or" 

channel    at    the( 

base  of  the  aper-  4 

ture.  3 

r Outer  lip  dilated;' 

4     the  margin  J- Cyclostoma.    Achalinella. 

L     spreading. 


s 


inM 


*  See  an  admirable  memoir  upon  this  genus  by  Mr.  Lowe,  in  the  Zoologi- 
cal Journal,  No.  xix,  p.  28U. 

N    3 


182  SHELLS    AND    SHELL-FISH.  PART   I 

If,  therefore,  the  Auricula  Midce*  and  JudcB  belong 
to  the  division  of  which  Melampus  is  the  type,  they  can 
be  so  arranged,  without  any  detriment  to  the  above  table. 
The  same  may  be  said  of  Scarabus.  We  have,  indeed, 
formed  this  arrangement  in  conformity  with  the  struc- 
ture of  the  animals,  rather  than  of  their  shells  ;  and 
resting  upon  this  principle,  we  deem  it  preferable  to  err 
on  the  safe  side,  rather  than  to  follow  previous  authori- 
ties on  the  subject. 

(169.)  The  next  genus,  Clausilia,  has  hitherto  been 
thought  to  form  a  part  of  the  Pupa;  the  two,  indeed, 
are  united,  yet  they  appear  to  form  distinct  groups.  The 
present  is  distinguished  by  having  the  aperture  ovate 
and  ear-shaped;  while  in  Pupa  it  is  almost,  if  not  quite, 
circular.  The  Clausilice,  as  a  whole,  possess  the  follow- 
ing characters  :  —  the  spire  is  invariably  longer  than  the 
aperture,  which  is  defended  in  all  but  one  instance  (^Ba- 
lia  Gray)  with  little  ridged  teeth,  usually  placed  upon 
feo^Alips;  they  are  all  small  and  slender  shells;  and  inhabit 
temperate  rather  than  tropical  climates.  We  arrange 
them  as  follows:  —  1.  Clausilia,  where  the  thickest  or 
largest  whorls  are  generally  in  the  middle  of  the  spire, 
the  tip  of  which  usually  falls  off  when  the  animal  has 
added  new  whorls  toitsshell, — a  wise  provision  of  nature, 
observes  Guilding,  "  since,  its  foot  being  short,  it  would 
not  have  the  power  of  drawing  along  so  heavy  a  shell :" 
the  aperture  is  usually  sinistral,  but  in  the  aberrant 
species  it  is  on  the  right  side  ;  it  is  very  small,  much 
contracted  above,  and  is  generally  beset  with  teeth  on 
both  its  sides.  In  Balia,  however,  these  teeth  disappear, 
and  the  mouth  is  dextral.  The  third,  Macrodontes  Sw., 
is  a  new  and  most  interesting  type,  uniting  the  com- 
pressed teeth  of  Clausilia,  with  the  form  and  size  of 
Auricula.     The  few  species  we  have  yet  seen  of  these 

*  The  representations  of  the  animal  of  Auricula  Midee,  given  by  M. 
Lesson's  Atlas  (pi.  9.  fig.  1.),  are  totally  different  from  that  of  M.  Quoy's  : 
the  former  has  the  teiitacula  and  eyes  of  a  Helix,  the  latter  those  of  Sca- 
rabus— There  must  be  some  great  error  in  one  of  these  !  Is  M.  Lesson's 
design  correct  ? 


CHAP.  VI.  SUB-GENERA    OF    CLAUSILIA.     '  183 

rare  and  remarkable  shells  are  all  from  Brazil;  and  they 
establish,  in  the  clearest  manner,  the  passage  between  the 
European  Clausili(S  and  the  South  American  Auriculce. 
We  have  now  arrived  at  that  particular  sub- genus  which 
is  to  connect  the  present  group  with  the  genuine  Piipte. 
This  union  is  effected  by  those  small  European  shells^ 
hitherto  placed  in  the  latter  genus,  which  we  have  sepa- 
rated under  the  name  of  Pupella.  This  sub-genus,  in 
fact,  may  be  looked  upon  as  the  common  point  of  union 
where  the  sub-families  Bulimince  and  Achatmcs  are 
united.  They  are  at  once  distinguished  by  having  both 
sides  of  the  aperture  toothed ;  and  not,  as  in  Pupa,  the 
inner  lip  only.  Some  uncertainty  hangs  over  what  shells 
are  the  true  types  intervening  between  Pupella  and  Balia. 
The  passage,  indeed,  is  very  easy,  if  we  suppose  it  to  be 
made  by  certain  little  shells  of  Europe  (as  the  P.  mus- 
corum,  fragilis,  dolium,  and  umhilicata  of  Drap.)  which 
have  no  teeth  on  the  outer  lip,  but  sometimes  one  on 
the  inner  ;  while  the  shortness  of  their  spires  would 
distinguish  them  from  Balia  :  or  this,  perhaps,  is  the 
place  where  some  of  the  smaller  shells,  analogous  to  our 
Gonospira,  should  be  placed  ;  at  all  events,  we  have  in 
Pupella  such  a  close  approximation  to  Balia,  that  the 
circle  of  the  genus  Clausilia  may  be  considered  almost 
perfect :  at  all  events,  we  cannot  consider  either  Alee  or 
Vertego  as  sub-generic  types,  merely  because  they  differ 
from  our  Pupella  by  the  position  of  their  aperture;  while 
Azeca  of  Leach,  as  a  sub-genus,  is  equally  questionable. 
We  presume,  therefore,  that  the  types  here  mentioned 
form  the  circle  of  Clausilia.  We  have  already  com- 
pared them  with  those  of  the  PupcE,  in  conjunction 
with  the  genera  of  the  Helicin^,  we  shall  now,  how- 
ever, bring  the  sub-genera  of  Pupa  and  Clausilia  more 
immediately  and  exclusively  together  ;  when  it  will  be 
more  readily  perceived  that  the  hiatus  between  Balia 
and  Pupella  might  be  filled  up  by  some  of  the  shells 
just  mentioned. 


N  4 


184. 


SHELLS    AND    SHELL-FISH. 


PART  1. 


Analogies  of  the  Genera  Clausilia  and  Pupa. 


Sub-genera  of 
Pupa. 

Sipho7iostoma. 
Megaspira. 

Gonospira. 


Analogies. 

f  Spire  exceedingly  long,  the  upper  > 
\     portion  deciduous.  J 

f  Spire  greatly  lengthened,  the  up-  7 
/      per  portion  persistent.  J 

Spire  moderate,  with  few  whorls, 'J 
the  tip  thick  and  obtuse;  thef 
aperture  generally  without  f 
teeth.  3 

"Spire  moderate,  but  with  manyT 


Sub-genera  of 
Clausilia. 

Clausilia. 


Balia.* 


rbpire  moiierate,  out  witn  manyT 
Pupa.  -^     wliorls  of  nearly  equal  thick.  >        Pupella. 

L    ness  3 


PUcadotnus. 


r  Whorls  few ;  the  outer  lip  dilated  7 
t     and  broadly  margined.  J 


Macrodontes. 


(170.)  Our  next  genus  is  Helicina, — a  group  of 
remarkable  shells^  of  which,  as  near  forty  species  are  now 
known,  the  sub-genera  may  be  advantageously  charac- 
terised. This  will  be  done  in  our  systematic  arrange- 
ment, and  in  the  mean  time  a  few  general  remarks  is  all 
that  we  can  here  insert.  Tfiey  are  small  helix-formed 
shells,  distinguished  by  their  semilunate  aperture,  which 
is  closed  by  an  operculum.  We  have  not  seen,  as  yet_, 
any  intermediate  form  which  renders  the  passage  between 
them  and  the  last  genus  sufficiently  clear.  The  animal, 
as  seen  in  H.occidentalis  (fig.  28.),  has  been  well  drawn 
by  Guilding;   it  has  only  two  tentacula,  with   the  eyes 


at  the  base.  In  this  respect  the  Helicince,  as  Cuvier 
observes,  have  a  close  affinity  with  the  Cyclostomes, 
many  of  which  are  also  turbinated  shells,  and  all  are 

*  I  should  conceive,  theoretically  and  analogically,  that  Bal/a  would 
represent  Gonospira  by  its  toothless  aperture ;  and  that  the  prototype  of 
Megaspira  would  be  perfectly  like  Clausilia,  but  without  any  teeth  or 
folds,  and  the  spire  (probably)  persistent. 


CHAP.   VI.  SUB-GENEBA    OF    CYCLOSTOMA.  185 

furnished  with  an  operculum.  Nothing,  perhaps, 
can  better  exemplify  the  artificial  nature  of  Cuvier's 
Pectinihranchia,  than  his  placing  Helicina  between  the 
two  fluviatile  genera  Ampullaria  and  Melania,  and  Cyclo- 
stoma  between  Scalaria  and  Valvata  ;  in  both  instances 
thrusting  in  a  group  of  land-shells  between  two  others 
which  only  inhabit  water.  This  is  the  more  inexcusable, 
because  it  did  not  originate  in  an  ignorance  of  the  ani- 
mals j  and  yet  he  observes  that  the  Helicince,  ^'^  judging 
by  the  shell,  are  Ampullaricp,  in  which  the  margin  of  the 
aperture  is  reflected."  *  The  only  reason  assigned  for 
placing  Cyclostoma  after  Scalaria,  is  '^  because  the  aper- 
ture is  entire,  nearly  or  quite  round,  and  operculated."  + 
This  is  quite  true,  but  every  student  will  readily  per- 
ceive that  this  is  merely  a  remote  analogy. 

(171  •)  The  genus  Cyclostoma,  like  the  last,  has 
the  sexes  distinct ;  but  this  is  the  only  one  character 
in  which  they  differ  from  the  other  pulmoniferous  land 
and  river  snails.  The  passage  between  this  and  the  last 
group  is  rendered  unquestionable  by  such  shells  as  Heli- 
cina'elegans  Gray,  which  has  the  characters  of  both 
united.  The  typical  Cyclostomce  are  spiral  shells,  the 
last  whorl  being  but  little  larger  than  that  which 
precedes  it.  The  orifice  of  the  mouth  is  circular, 
and  is  closed  by  a  horny  operculum.  The  pillar  is 
often  wanting ;  but  this  variation  occurs  in  species 
so  close  to  each  other,  that  it  cannot  be  considered 
a  sub-generic  character.  They  are  usually  found  in 
dry  arid  situations:  the  island  of  Malta  abounds  with 
them,  where  thousands  may  be  gathered  on  the  scanty 
herbage  of  the  rocks ;  and  many  elegant  species  oc- 
cur in  the  mountains  of  Jamaica.  On  coming  to  the 
aberrant  sub-genera,  we  find  great  diversity  in  the  form, 
although  none  in  the  aperture.    In  Cyclophora,  the  shells 

*  Cuvier  further  remarks  that  tlie  organs  of  respiration  are  arranged  as 
in  the  Cyclostomce,  and,  like  the  latter,  they  can  live  out  of  water.  That 
these  two  genera  are  naturally  united,  both  by  the  animal  and  the  shell,  is 
thus  admitted,  while  we  can  only  say  that  they  are  both  as  terrestrial  as 
the  garden  snail ;  they  cannot,  in  fact,  live  out  of  the  air,  as  we  always 
killed  the  animals  of  our  specimens  by  plunging  them  into  water. 

t  GrifF.  Cuv.  xii.  p.  58. 


186 


SHELLS    AND    SHELL-FISH. 


PART  I. 


are  turbinated,  and  resemble  those  of  Helix,  although 
the  tip  of  the  spire  is  acutely  conical,  and  not,  as  in  the 
common  snail,  depressed.  These  obviously  lead  to  the 
typical  sub-genus  Cyclostoma ;  and  these  latter,  again,  to 
the  singular  9,\ih-geT\\\s  Megalomastoma,  —  another  ad- 
mirable group,  detected  and  beautifully  illustrated  by 
Guild ing  ;  it  is  the  representative  of  Pupa,  from  which 
it  is  distinguished  by  possessing  a  horny  operculum. 
Cyclotus  of  the  same  accurate  zoologist  is  another 
remarkable  type :  it  is  so  much  depressed,  that  it  almost 
resembles  a  Planorhis,  and,  from  not  having  any  pillar, 
the  umbilicus  is  open  to  the  terminal  whorl :  the  oper- 
culum is  shelly  ;  and  although  the  aperture  is  round 
and  thickened,  the  inner  lip  is  carried  upwards  in  the 
form  of  a  little  siphon  :  this  is  very  remarkable  in  a 
species  we  possess  from  India,  and  in  another  from  the 
West  Indies.  We  are  disposed,  indeed,  to  consider 
this  and  Cyclophora  to  be  the  two  typical  forms  of  the 
whole  group  which  represent  Planorhis,  just  as  the 
LucernincB  do  in  the  entire  family  of  Helicidce. 
Guilding  founded  his  group  upon  one  species  (C.'fus- 
cescens),  which  he  found  "  with  the  spire  corroded,"  in 
the  woods  of  St.  Vincent ;  and,  unfortunately,  all  the 
specimens  found  by  him  afterwards  were  dead  shells,  so 

that  the  animal  is  still  unknown. 
3Iegalomastoma  appears  immedi- 
ately to  follow  Cyclostoma,  because 
the  M.  suspensitm  Guild.,  in  its 
shell,  is  a  Cyclostoma ;  but  the 
M.  hrunnea  Guild.,  which  is  ob- 
viously the  type,  is  so  elongated  as 
to  resemble,  at  first  sight,  a  Pupa. 
The  animal  of  M.  suspensum  is 
often  found  suspended  by  glutinous 
threads  (fg.  29-);  it  has  the  mouth 
rather  elongated,  proboscis-like,  but 
deeply  cleft ;  the  two  ten  taenia 
rather  long,  and  the  eyes  at  their 
base.     Having  now  concluded  the  survey  of  the  four 


CHAP.    VI. 


THE  LIMNACIN^. 


187 


great  divisions  of  the  Helicid^,  which  include  all  the 
land-shells  and  slugs,  we  may  enter  upon  the  fifth  and 
last,  which  are  aquatic. 

(172.)  TheLiMNAciN^is  that  sub-family  which  con- 
tains the  whole  of  those  spiral  fluviatile  shells  which, 
like  all  the  Helicidce,  respire  by  a  lateral  perforation. 
It  is  difficult  for  the  student  to  distinguish  these  river 
shells  from  those  of  the  fluviatile  genera  in  the  next 
family  ;  but  they  are  in  general  much  thinner,  and  in 
no  instance  have  the  Limnacinw  even  the  vestige  of  an 
operculum.  Like  the  Cyclostomce,  these  animals  have 
but  two  tentacula ;  but  they  are,  in  general,  very  short 
and  broad,  having  the  eyes  at  their  base  :  their  shells  are 
all  very  thin,  devoid  of  any  bright  colour,  and  the  aper- 
ture is  always  simple,  —  that  is,  without  any  thickened 
margin.  They  appear  to  arrange  themselves 
into  the  following  genera  :  —  1 .  Planorbis, 
where  the  shell  is  disk-shaped,  and  with- 
out any  pillar,  as  in  our  common  P.  cor- 
neus.  (fig.  30.)  2.  Limnceus,  having  a 
very  large  and  wide  aperture  on  the  right 
side,  and  the  basal  whorl  so  large  as  to 
contain  the  whole  animal.  3.  Physa,  where 
the  aperture  is  much  smaller,  the  base  contracted,  and 
the  mantle  so  large  that  its  two  lobes  fold  over  the 
shell.  In  the  fourth  sub-genus  Potomophila,  the  shell 
very  much  resembles  the  last,  but  the  pillar  is  marked 

with  a  distinct  plait  or  fold  in 
the  middle ;  the  only  species  we 
are  yet  acquainted  with,  istheCo- 
novulus  buHmo'ides  *  of  Lamarck. 
{fig.  31.)  In  this,  as  in  innu- 
merable instances,  analogy  has 
been  mistaken  for  affinity.  It 
is  clear  there  is  a  resemblance  between  this  and  the 
sub-genera  Auricula  and  Conovidus ;  but  we  think 
there  is  no  doubt  that  this  is  a  fluviatile  shell,  and,  but 


*  Ency.  Meth.  pi.  459.  fig.  7- 


188 


SHELLS    AND    SHELL-FISH. 


PART  I. 


for  this  fold  on  the  pillar,  it  could  not  be  distinguished 
from  a  Limnceus.  The  fifth  and  last  type  is  Ancylus, 
composed  of  the  freshwater  limpets  (^fig.  32.),  not  even 

mentioned  by  Cuvier,  but  con- 
stituting one  of  the  most  re- 
markable divisions  of  the  whole 
group. 

(173.)  The  five  genera, 
placed  opposite  to  those  of  the 
genera  of  AchatincB,  and  the 
sub-families  of  the  Helicidce, 
will  be  found  to  represent  each 
other  thus :  — 


Genera 
of  the 

I.imnacince. 

Planorbis. 

Ancylus. 

Pototnophila. 

Physa. 

Limrueus. 


Analogies  of  the  Limnacin^. 


Analogies. 


Sub-families       Genera 
of  the  of  the 

Helicidce.        Achatina. 


r  Shell    depressed     disk-like ;  |  Lucernin^.     Cyclostoma. 
l_     aperture  round.  3 

f  Shell  fragile,   much  smaller  7  Lt^.^^iNiE.        Helicina. 
(_     than  the  animal.  y 

}  Shell  thin  ;  aperture  large  ; )  Lj^n^cin^.     ClausUm. 
i     pillar  plaited.  3 


(•Outer  lip  thin;    last  whorl  7  ^^„^^,^^ 
i     contracted.  3 

Outer    lip    reflected ;    basal 


Achatina. 


{ 


whorl  very  large. 


i« 


ELiciN.£.      Bulimus. 


The  general  analogies  of  the  whole  group  may  be 
first  slightly  touched  upon.  The  LimnacincE  occupy 
that  station  in  the  circle  of  the  Helicidce,  which  corre- 
sponds to  that  of  the  Cephalopoda  in  the  great  tribe  of 
Testacea.  Hence  they  are  all  aquatic  animals  ;  and  if 
this  analogy  is  correct,  it  follows  that  Planoi-his  is  the 
typical  group,  because,  in  their  flat  discoid  shells,  they 
perfectly  agree  with  the  equally  depressed  and  convo- 
luted Nautili.  We  have  seen,  also,  that  in  Ci/rlotus 
a  strong  approach  is  made  to  this  very  same  structure. 
The  little  shells  of  several  of  the  slugs  (Limacincp),  if 
no  regard  be  paid  to   the   animals,  might  very  well  be 


CHAP.  VI.   THE  LIMACIN^,  OR  NAKED  SLUGS.     189 

taken  for  freshwater  limpets ;  so  that  the  analogy  is 
most  complete.  Potomophila,  again^  is  the  only  type 
having  any  fold  upon  the  pillar ;  and  Clausilia  is  the 
only  genus  so  distinguished  among  the  Achatince.  It  is 
the  excessive  enlargement  of  the  body-whorl  which 
gives  such  a  peculiar  character  to  the  turbinated  snails  ; 
and  this  renders  them  distinct  from  the  Achatince :  and 
the  very  same  disproportion  is  observed  in  all  the 
typical  examples  of  Limncpus,  of  which  the  common 
L.  stagnalis  is  a  familiar  example.  The  near  approxi- 
mation of  the  amphibious  genus  Succinia  to  the  group 
we  have  now  gone  through^  is  abundantly  obvious. 
While,  from  possessing  four  tentaeula,  with  the  eyes 
pedunculated,  it  cannot  be  brought  within  the  limits  of 
the  freshwater  shells  ;  it  is,  in  short,  as  Cuvier  has 
happily  expressed  it,  ''^  a  Testacella,  with  a  very  large 
shell."  As  the  systematic  definitions  will  be  here- 
after given,  we  need  not  dwell  longer  upon  this  sub- 
family. 

(174.)  The  sub-family  of  Limacina;  which  contain 
the  naked  slugs,  is  admitted  to  be  such  a  natural  group^ 
that  this  part  of  our  survey  may  be  considerably  abridged. 
The  first  of  the  typical  genera  appears  to  be  Limcijc, 
where  the  tentacula  are  four,  and,  in  general,  the 
vestige  of  a  shell  is  placed  near  the  extremity  of  the 
body.  The  second  is  typically  represented  by  the 
genus  Herpa  of  Guilding,  in  which  the  tentacula  are 
either  entirely  wanting,  or,  as  in  the  sub-genus  On- 
chidium,  they  are  only  two  in  number,  and  very  short. 
The  determination  of  Herpa,  as  connected  to  Li  max, 
is  one  of  the  most  important  discoveries  in  mala- 
cology that  has  been  made  for  many  years,  not  merely 
as  to  the  fact  itself,  but  to  the  inferences  to  which  it 
leads :  it  may  be  considered,  in  short,  as  the  germ, 
or  first  incipient  developement  of  this  immense  family, 
from  which  all  its  innumerable  modifications  branch 
off.  Its  analogy  to  Planaria  among  the  Pareiichymata 
is  abundantly  obvious ;  a  relation  well  understood  by 
its  learned   and  acute   discoverer,  who  thoroughly  un- 


190  SHELLS    AND    SHELL-FISH.  PART  I. 

derstood  the  difference  between  analogy  and  affinity*, 
so  lamentably  confounded  by  so  many  other  naturalists^ 
even  of  the  greatest  reputation.  The  analogy,  again, 
which  the  large  coriaceous  mantle,  or  shield,  of  Onchi- 
dium  has  to  the  Chitons  need  hardly  be  adverted  to. 
The  three  aberrant  genera,  Vitrina  Drap.,  Stenopus 
Guild.,  and  Succinea  Drap.,  have  turbinate  shells,  nearly 
or  quite  sufficient  to  include  their  bodies ;  but  these 
coverings  are  generally  thin  and  semi-transparent,  with 
a  wide  aperture,  a  very  short  or  small  spire,  and,  ge- 
nerally, with  only  the  vestige  of  a  pillar.  For  the  dis- 
covery of  the  singular  animal  of  Stenopus  cruentatus  t 
(^fig.  SS.\  science  is  likewise  indebted  to  the  lamented 


Guilding:  it  seems  intermediate  between  Vitrina  and 
Succinea,  and  will  thus  stand  as  the  most  aberrant  of 
the  whole.  The  connection  of  this  sub-family  to  the 
freshwater  snails  is  obviously  effected  by  Succinea; 
while  Vitrina  leads  immediately  to  Leiostoma,  among  the 
land  volutes.  The  sub-genera  not  having  yet  been 
determined,  we  shall  pass  at  once  to  the  fifth  division, 
which  closes  the  circle  of  the  Helicidcp. 

( 1 75.)  The  terrestrial  volutes,  or  lamp-snails,  Lucer- 
NiN^,  were  named  by  Humphreys, — a  name  we  retain 
for  the  whole  group,  which,  as  we  have  already  seen, 
constitute  a  sub-family.:};  They  are  well  distinguished 
from  the  typical  HelicincE  by  three  characters,  any  two 

*  "  Genus  Planariis  facie  quam  plurimutn  analogiim,  ut  Limacides  re- 
spirationis  modo,  locis,  moribusque  omnino  affinc." — Guildin<^  MSS. 

f  See  figures  and  description  in  Zuol.  Journal,  iii.  pi.  l5.  figs.  1 — 5. 

X  Lamarck  suhsequently  used  the  name  Caracolla,  which  Ferussac 
wished  to  set  aside  for  that  of  llclicodonta,  a  name  which,  even  had  it  the 
priority,  implies  two  errors  ;  — first,  that  they  belong  to  the  typical  Helices; 
and  secondly,  that  they  all  have  teeth  :  we  consequently  cannot  adopt  the 
innovation. 


CHAP.  VI.  THE    LUCERNIN^.  IQl 

of  which,  in  doubtful  cases,  will  almost  always  he  a 
sufficient  guide :  — 1 .  The  very  marked  depression  of  their 
whole  form,  and  the  great  number  of  the  spiral  whorls. 
2.  The  possession  of  teeth  either  on  one  or  on  both  sides 
of  the  aperture :  and,  3.  The  granulated,  or  distinctly 
striated,  surface  of  the  shell.  As  our  analysis  has  not 
been  carried  down  to  the  location  of  all  the  sub-genera, 
we  shall  merely,  in  this  place,  enumerate  the  primary 
groups  or  genera,  with  some  few  of  the  sub-genera,  leaving 
the  rest  for  the  more  systematic  department  of  the  vo- 
lume. 

(176.)  The  groups  which  appear  to  rank  as  genera, 
and  which  are  therefore  the  first  divisions,  are  the  fol- 
lowing :  —  1 .  Lucerna,  having  the  shell  flattened  and 
orbicular,  the  margin  always  carinated,  and  generally 
sharp ;  the  whorls  numerous ;  the  surface  granulated, 
but  never  striated ;  and  the  aperture  usually  toothed,  but 
the  teeth  confined  to  the  inner  lip.*  2.  Lucernella, 
equally  depressed  with  the  preceding,  but  the  margin  of 
the  body-whorl  is  rounded  and  convex ;  the  outer  lip 
is  always  toothed,  and  there  are  opposite  teeth  on  the 
inner  lip.  These  appear  the  two  typical  divisions.  The 
three  aberrant  are,  the  broad-lipped  species  of  Ferussac's 
sub-genus  Helicella,  having  the  body-whorl  unusually 
large  in  proportion  to  those  of  the  spire,  which  is  flat- 
tened ;  the  umbilicus  deep ;  the  outer  lip  spreading, 
and  diflPuse,  but  rarely  provided  with  any  toothlike  pro- 
jection :  these  form  our  genus  Hemiodon.  The  next, 
or  most  aberrant  type,  is  composed  of  a  part  of  Ferus- 
sac's Helicogena,  where  the  shell  is  granulated,  the  spire 
depressed,  and  the  outer  lip  marked  at  its  base  with 
toothlike  notches ;  the  spire  is  very  small,  and  hardly 
makes  three  volutions :  this  is  our  genus  Thelidonius. 
The  wide  aperture  of  these  prepare  us  for  Leiostoma, 
having  the  aperture  remarkably  large  and  particularly 
smooth  and  glossy,  while  the  glazing  of  the  inner  lip  is 
extended  very  much   beyond   its  usual  circumference. 

*  Except  in  Anastoma,  which  represents  Pupa  and  ClausUta. 


192  SHELLS    AND    SHELL-FISH.  PART  1. 

This  latter  character  is  highly  important,  as  showing  the 
analogy  of  Leioatoma  to  the  LimnacincB,  and  its  affinity 
to  the  half-testaceous  slugs,  or  the  Limacince. 

(177-)  Looking  to  the  above  genera,  with  reference 
to  their  analogy,  they  appear  to  represent  the  following 
divisions  in  their  own  family,  and  in  t^e  tribe  of  the 
Zoophaga :  — 

Analogies  of  the  Lucernin^,  or  Land  Volutes. 

Genera  of  the  Analogical  Characters.  ^"'"'SvJ'lwLf^  ^^^ 

Lucerntnce.  "  Helicidce. 

LUCERNA.  [  ^^'^?.T:1T  ^^''  ''°"''  '   ''''°'"^'  \  ACHATIN^. 

TII^FR^^RIIA  J" Spire   depressed;     the    margins?         Helioivt 

1.UCEKNELLA.  ^     convex ;  whorls  few.  j         helicinje. 

Hemiodon.  Shell  discoid ;  the  spire  depressed.  LuceRiMN^. 

Thelidomus.  Spire  of  very  lew  whorls.  LiMAciNiE. 

T  ^.^  ^^,.  ("Aperture  very  effuse;  inner  lip7         t,,.x,.^.»,^ 

Leiostoma.  y     Spreading.  ]        Lim^acin^. 


(178.)   The  typical  genus  Lucerna  has  one  peculiar 
character,  —  that  although  its   outer   lip   is  in   general 
toothed  or  plaited,  these  plaits  are  never  seen  upon  the 
inner  lip,  or  that  part  of  the  body-whorl  which  forms 
the  opposite  side  of  the  aperture.     They  are  the  largest 
shells  of  this  sub-family,  and  are  particularly  abundant 
in   the  West  India  islands.     Although   decidedly  de- 
pressed shells,  their  spiral  whorls  are  numerous,  and  are 
very  progressively  graduated.      We  separate  them  into 
the  five  following  sub-genera:  —  In  Dismdoma,  the  cir- 
cumference is  carinated,  the  aperture  angular,  and  without 
teeth ;  and  the  edge  of  the  outer  lip  but  slightly,  if  at  all, 
reflected.    In  Lucerna,  the  teeth  on  the  edge,  or  within 
the  outer  lip,  are  very  evident.      In  Anqstoma,  they  are 
extended   all   round   the    aperture,    which    is    likewise 
turned,  so  as  to  be  nearly  on  the  same  plane  as  the  spire. 
Leaving  these,  we  have  an  analogous  form  to  Thelidomus 
in  several  small  toothless  Helices  L.  (our  Lnridella),  but 
which  evidently,  by  their  spire,    belong  to  this  group. 
Caracotla  completes  the  circle  by  uniting  to  Discodoma, 


CHAP.   VI.  THK  LUCEBNELLiE.  19-^ 

from  which  it  is  nevertheless  separated  by  its  circular 
aperture,  analogous  in  this  group,  to  Cydostonia.  As 
this  is  the  European  type,  we  have  preferred  retaining  to 
it  the  sub-generic  name  of  Caracolla,  that  the  nomen- 
clature of  such  well-known  species  should  not  be  dis- 
turbed. The  whole  group  is  composed  of  granulated 
shells. 

(179-)   Ii^  the  second,  or  sub- typical  group,  we  shall 
find  five  sub-genera  agreeing  with  those  of  the  last.      As 
a  general  character,  the  Lucernellce  vt\?Ly  be  known  by  the 
inner  lip,  no  less  than  the  outer,  being  provided  Avith 
teeth  :  those  on  the  former  are  either  one  or  (very  rarely) 
two,  placed  almost  transversely,  as  if  to  guard  the  en- 
trance to  the  shell  by  rendering  the  aperture  remarkably 
narrow ;  the  teeth  on  the  outer  lip  are  situated  at  its  in- 
ner edge,  and  have  no  corresponding  indented  grooves  (as 
in  Lucerna)  on  the  outer  surface.     All  the  Lucernellce, 
likewise,  are  convex  on  their  sides,  not  carinated.      It  is 
only  in  the  sub-genera  Heniiq/chi  and  LuckleUa  that  the 
inner  teeth  disappear  ;  but  the  union  of  the  first  of  these 
two  with  Cyclodoma  is  so  obvious,  that  they  cannot  be 
placed  in  different  genera.      The  first  form  on  quitting 
Anastoma  is  Polydontes,  of  which  the  type  is  that  sin- 
gular shell  P.  imperaior  oi  Montfort;  it  is  remarkable  for 
its  aperture  being  surrounded  by  nodulous  teeth,  obtuse, 
and  resembling  large  granules,  while  those  of  Anastoma 
are  more  properly  folds  or  plaits  :   following  this  comes 
Lucernella ,  where  the  form  of  the  shell  is  often  globose, 
the  umbilicus  closed,  and  the  teeth  very  complicated:  these 
lead  to  the  greatly  depressed  form  of  Cyclodoma,  where 
the  shape  is  sometimes  as  discoid  as  in  the  well-known 
genus  Pktno7-his.    These  shells  are  almost  always  striated; 
and,  although  small,  are  highly  interesting.     A  great 
number  of  species  inhabit  the  mountains  of  North  Ame- 
rica and  Madeira,  but  probably  not  one  half  of  those 
that  exist  have  yet  been  discovered.    In  Hemicycfa,  the 
internal  or  left-hand  tooth  either  entirely  disappears,  or 
is  reduced  to  a  little  tubercle  ;  the  cuter  lip  makes  a  bold 
and  dilated  semicircle,  the  margin  of  which  is  broad  and 

o 


194)  SHELLS    AND    SHELL-FISH.  PART  I. 

flattened,  without  being  absolutely  reflected  backwards. 
Lastly,  we  venture  to  place  a  few  small  shells,  having 
something  the  aspect  of  Helicince* ,  as  a  fifth  type,  under 
the  name  of  Lucidella;  they  differ  from  the  last  by  the 
comparative  smallness  of  the  aperture,  which  has  one  or 
two  small  teeth  on  the  outer  lip,  but  none  on  the  inner  : 
these  appear  to  pass  into  Thelidonta  ;  and  in  this  man- 
ner do  we  conceive  the  whole  form  a  circle.  Not 
having  yet  completed  our  analysis  of  the  three  aberrant 
genera,  Piis'wdon,  Tlielidomus,  and  Leiostoma,  we  shall 
not  at  present  attempt  to  designate  their  sub-genera.  De 
Ferussac  has  adopted  a  modification  of  Humphrey's 
name  of  Lucerna  (which  he  writes  Lucena)  for  that 
group,  part  of  which  we  here  call  Leiostoma  ;  but  how 
far  he  is  correct  in  placing  the  richly-coloured  shells 
upon  his  plates  12,  13,  and  14.  with  that  which  we  de- 
signate as  the  type — may  well  be  questioned.  The  dis- 
torted body- whorl  of  Thelidomus,  and  its  serrated  outer 
lip,  render  it  analogous  to  Lucidella,  from  which  it  differs 
altogether  in  the  few  and  unequal  volutions  of  its  spire. 
The  most  interesting  genus,  however,  is  that  of  Hemio- 
don,  which  has  a  large  dilated  aperture,  the  spire  scarcely 
raised,  and  a  gibbous  prominence  more  or  less  developed 
at  the  base  of  the  outer  lip.  This  is  the  last  remnant 
of  the  toothed  aperture  so  common  in  this  sub-family ; 
and  accordingly  prepares  us  for  the  true  Helicellce,  which 
compose  the  first  genus  among  the  HeUciu<v.  Thus  do 
the  LucERNiNyE  foHu  their  circle  of  affinity,  connected 
on  one  side  to  the  slugs  by  Leiostoma,  which  passes 
into  Vitrina,  and  on  the  other  to  the  land  helixes^ 
as  just  stated. 


*  Such  as  Helicina  aureola,  Zool.  Journ.  i.  p.  Ifi.  f.  13. 


195 


CHAP.  VII. 

THE    PHYTOPHAGOUS    GASTROPODS    CONTINUED.  THE    TUREID-«, 

OR    MARINE    SNAILS. 

(180.)  The  family  of  Turbid^  succeeds  the  last, 
and,  like  them,  is  composed  of  spiral  shells,  destitute 
of  any  pearly  lustre,  with  the  aperture  closed  by  an 
operculum  * :  the  differences,  however,  are  so  slight, 
that  the  two  families  can  scarcely  be  distinguished  by 
their  shells  alone.  The  animals  of  the  Turbidce,  hov/- 
ever,  are  remarkably  dissimilar  from  those  of  the 
Helicidcp  :  they  breathe  by  gills,  like  all  the  zoopha- 
gous  families  ;  and,  like  them,  the  mouth  of  the  major 
part  is  furnished  with  a  respiratory  siphon,  and  even 
a  probosciform  mouth :  the  tentacula  are  only  two  ; 
and  the  eyes  are  either  basal,  or  on  the  sides  of  the 
tentacula.  The  animals,  in  short,  often  exhibit  the 
carnivorous  structure  of  the  Zoophaga,  while  their  shells 
are  completely  those  of  the  phytophagous  tribe  :  it  is 
thus  that  the  two  groups  are  connected.  The  whole  of 
this  assemblage  are  comprised  in  the  following  sub-fami- 
lies : — The  first  is  uncertain.  2.  The  AmpullarincB,  or 
apple-snails.  3.  The  Melaniance,  or  black  snails.  4.  The 
Turhince,  or  winkles.  5.  The  lantltincE,  or  Oceanic 
snails.  A  general  analysis  of  these  will  now  be  given  ; 
this  investigation  we  were,  in  a  manner,  forced  into, 
from  the  impossibility  of  discovering  any  bond  of  union 
or  of  affinity  between  the  heterogeneous  genera  of  the 
Turbidce,  as  they  now  stand  in  our  conchological 
systems. 

(181.)     The  first  primary  division    by  which    this 
family  may  be   united  to  the  fluviatile  Limnacince,  is 

*  Except  in  Melampus,  and  probably  lanthina, 

o  2 


196  SHELLS    AND    SHELL-FISH.  PART  I. 

somewhat  uncertain.  There  are  several  fossil  genera, 
as  Enomphalus  Sow.,  Orhis,  and  Planaria*  of  Lea,  of 
a  discoid  shape,  whose  animals  are  quite  unknown,  and 
will  ever  be  so,  if  no  recent  species  are  discovered. 
Their  shells,  indeed,  are  intermediate  between  those  of 
the  Ampullarince  and  the  Limnacince  ;  but  then  this  dis- 
coid shape  is  found  in  so  many  different  families,  that 
their  location  here  would  be  entirely  conjectural.  On 
the  other  hand,  we  have  our  choice  of  Valvata  and 
'Thalliceraj:  the  first  appears  to  us  more  like  one  of  the 
genera  of  the  AmpuUarina ;  while  the  extraordinary 
animal  of  the  latter,  and  the  singidarity  of  the  shell, 
leads  us  to  view  it,  with  ^M.  Deshayes,  more  as  the 
representative  of  a  sub-family  than  of  a  genus.  May 
this,  again,  be  the  natural  station  of  the  semi-aquatic 
genera  Melampus,  Scarahus,  Sec,  whose  animals  have 
certainly  a  strong  resemblance  to  those  of  the  LimnacincE  ? 
Into  these  theoretical  questions  we  dare  not  enter ; 
difficulties  are  opposed  to  the  adoption  of  each  of  these 
theories  ;  and  we  shall,  therefore,  choose  that  which 
appears  to  us,  upon  the  whole,  least  liable  to  objection, 
— namely,  the  supposition  that  Thallicera  stands  inter- 
mediate between  the  AnipuUarincB  and  the  Limnacince, 
The  animal  of  Thallicera,  like  the  Limnacince,  is  her- 
maphrodite :  the  head  is  large,  flat,  cleft  in  two  lobes, 
which  bear  the  two  sessile  eyes  ;  but  these  are  without 
any  appearance  of  tentacula  ;  the  oper- 
culum is  horny;  and  the  animal  is  ma- 
rine. Such  is  the  substance  of  the  in- 
teresting facts  made  known  by  ?J.  Quoy, 
who  found  the  T.  Avellana  {fig.  o-i.) 
in  abundance  on  the  coasts  of  New 
Zealand.  That  it  is  thus  allied  both 
to  the  operculated  marine  Pectinibranchia    by  its  shell 


»  This  name  cannot  be  retained,  having  been  long  ago  applied  to  a  well- 
known  genus  among  the  ParcncUymata  of  Cuvier,  and  of  this  work 

t  M.  Qiioy,  among  his  other  brilliant  oiscoveries  in  malacology,  has  the 
honour  of  making  known  the  animal  of  Ampullaccrn  I  trust  he  will 
excuse  my  proposing  Thallicera,  as  a  name  not  liable,  like  the  above,  to  be 
confounded  with  Anipullaria. 


CHAP.   VII.        THALLICERA. AMPULLARIN^. 


197 


and  its  habitat,  and  to   the  puhnonary  fluviatile  Lim- 
nacince  by  its  animal,  there  can  be  no  doubt. 

(182.)  The  shape  of  the  AmpullarincB  is  most  like 
the  garden  snails  ;  they  are  generally  globose,  the  spire 
very  short,  and  the  body-whorl  enormous.  ISIany  of 
them  are  very  large,  and  none  are  of  a  small  size.  They 
abound  in  the  rivers  of  tropical  countries,  both  of  the 
New  and  the  Old  World.  Guilding  has  admirably  de- 
lineated the  animal  of  this  and  the  sub-genus  Ceratodes, 
and  has  thus  determined  the  latter  to  be  a  representa- 
tive only  of  PlanorUs.     TheanimalSj  in  fact  (^fig.  35.), 


of  the  present  group  are  furnished  with  a  respiratory 
siphon  (a)  ;  and  are,  no  doubt,  carnivorous,  as  well  as 
herbaceous.  Most  of  them  have  the  operculum  horny, 
but  in  some  it  is  shelly  ;  and  this,  joined  to  the  thin- 
ness or  thickness  of  the  outer  lip,  may  serve  to  dis- 
tinguish the  sub-genera.  The  genus  Paludina  seems 
to  represent  the  last  in  the  rivers  of  Europe,  and  is 
well  distinguished  by  the  greater  length  of  the  spire,  as 
seen  in  our  native  P.  vivipara;  but  there  are  many 
exotic  species  :  the  aperture  is  narrowed  above,  and 
generally  protected  by  a  horny  operculum.  Nematura 
appears  a  sub-genus  whose  operculum  is  shelly,  and 
the  aperture   still  more    contracted.     With  this  genus 


o  a 


198 


SHELLS    AND    SHELL-FISH. 


PART  I. 


we  also  place  the  European 
P.  impura  Lam.^  and  the 
West  Indian  P.  parmda  of 
Guilding  (^^.36.),  the  ani- 
mal of  which,  according  to 
his  drawings,  has  the  tenta- 
cula  unequal,  —  that  nearest 
the  pillar  being  almost  twice 
the  length  of  the  other.  It 
is  as  a  sub-genus,  also,  of 
Paludina,  that  we  are  dis- 
posed to  regard  Valvata. 
The  shells  of  this  last  remarkable  type  are  mostly  of  the 
same  form  as  many  of  the  helix-like  Cyclostomce ;  the 
aperture  is  also  round,  and  closed  with  an  operculum. 
The  animal,  which  we  have  not  seen,  is  described  by 
Midler  as  having  the  branchia,  or  gills,  pectinated,  and 
projecting  from  under  the  mantle,  floating  externally, 
and  vibrating  every  time  the  animal  breathes  :  on  the 
right  side  of  the  body  is  a  filament,  which  resembles 
a  third  tentaculum. 

(183.)  Our  third  sub-family,  Melanian^,  is  com- 
posed of  those  long-spired  fluviatile  shells  which  form 
the  genera  il/e/anm  and  Melanopsis,  together  with  that  of 
Planascis,  as  the  most  aberrant,  and  two  others  now  first 
designated  as  Paludomus  and  Ccrithidea.  This,  which 
we  think  is  the  typical  sub-family  of  the  Turbidce,  is 
so  numerous,  that  it  becomes  necessary  to  characterise 
the  sub-genera  ;  for  without  this,  the  theory  of  their  re- 
presentation could  not  be  rendered  intelligible.  The 
animals  of  these  shells  are  well  distinguished  from  the 
last,  by  having  their  eyes  more  developed,  and  placed  in 
the  middle  of  the  tentacula,  while  the  mouth  is  elongated 
in  the  form  of  a  proboscis.  The  genus  which  makes  the 
nearest  approach  to  the  AmpnUarino',  in  the  globular 
form  of  the  shell,  the  short  spire,  and  the  rotundity  of 
the  aperture,  is  that  of  Paludomus  Sw.,  formed  to  re- 
ceive those  short-spired  shells  which  at  present  are  placed 
in  that  of  Melania.    The  American  species  form  the  sub- 


CHAP.    Vir.        MELANIANiE.  THE    GENERA. 


199 


gemis  J  ncu/osa  of  Say  {fig.^l-a)* ,  and  almost  resemble 
nerits.  Notwithstanding  the  thickness  of  these  shells^  the 
outer  lip  is  unusually  thin,  and  the  inner  is  like  that  of  a 

Purpura,  being  broad  and  flat- 
tened. One  or  two  species  now 
before  us  are  so  like  young  ma- 
rine turbos,  that  none  but  a 
practised  eye  would'  distinguish 
them.  They  are,however,strictly 
fluviatile  shells,  having  a  horny 
operculum ;  and  are  abundant  in  the  Ohio.  The  next  sub- 
genus is  Pahidomus  proper  (6) :  they  differ  from  Anculosa 
in  being  sub-spiral  like  the  Bulimi,  and  in  having  both 
lips  thickened,  although  not  margined  by  a  rim  ;  the 
outer  one  is  slightly  reflected  and  crenated,  and  the  in- 
ner perfect  and  convex  :  these  seem  peculiar  to  the  Indian 
rivers.  In  the  next  sub-genus,  Hemimitra,  the  general 
form  of  Pahidomus  is  preserved,  but  the  whorls  are 
coronated  by  spines.  The  whole  are  readily  distinguished 
from  the  next  genus,  by  not  having  the  outer  lip  dilated 
at  its  base,  the  inner  lip  complete,  the  aperture  wide,  and 
the  spire  always  shorter  than  the  body-v*'horl,t 

(184.)  The  true  genus  Melania  comes  next.  Amid 
the  great  diversities  of  forms  it  contains,  even  as  we 
now  intend  to  restrict  it,  there  may  be  detected  four,  if 
not  five,  types  or  sub-genera;  yet,  with  one  exception |, 
they  are  all  possessed  of  an  entire  aperture,  and  are  more 
or  less  spiral.  The  animal,  according  to  Cuvier,  has  a 
proboscis-like  inouth,  and  the  tw^o  tentacula  bear  the  eyes 
half  way  on  their  external  side ;  the  aperture  is  always 
oval,  the  outer  lip  thin,  and  is  generally  much  dilated  at 
the  base.  The  five  types  of  form,  or  sub-genera,  appear 
to  be  these: — 1.  Melacantha  ;  2.  Melania;  S.  Po- 
tadoma  ;   4.  Hemisinus ;   and,  5.  Melanella. 

(185.)  The  first  type  which  meets  us  after  quitting 
Paludomus   is  Melacantha,  of    which  the  well-known 

*  I  consider  this,  however,  as  a  form  between  Paludinn  and  Paludomus. 
t  'Melanin  conicii,  globulosa,  and  retusa,  of  Mr.  Gray,  Griff.  Cuv.  pi.  14., 
belong  to  this  group. 

X  Tlie  sub-genus  Hemisinus. 

0  4 


200  SHELLS    AND    SHELL-FISH.  PART  I. 

Melania  amarida  and  setosa  are  typical  examples.  The 
spire  is  short,  and  the  volutions  coronated  ;  the  inner  lip 
is  merely  a  thin  glazing  ;  and  the  base  of  the  pillar  is  flat- 
tened. It  will  be  remembered  that  Hemimitra  is  the 
coronated  type  of  Paludomus,  and  is  so  like  Melacan- 
tha  on  a  superficial  glance,  that,  but  for  the  difference  in 
their  apertures,  they  might  be  taken  for  species  of  the 
same  genus.'  From  these  we  are  gradually  led  to  the 
typical  division  of  Blelania,  w^hose  spire  is  often  as  long 
as  in  Turritella.  These  shells  are  much  lighter  than 
those  of  the  next  group,  Potadoma,  which  are  more  solid 
in  their  substance;  the  base  of  the  pillar  is  not  depressed 
or  broad,  but  convex  and  comparatively  thin  ;  it  is  like- 
wise, in  most  of  the  species,  much  straighter,  while  the 
base  of  the  outer  lip  is  more  dilated.  All  the  species  we 
have  yet  seen  of  this  sub-genus  are  decollated.  We 
regard,  as  the  most  typical  character,  a  slight  thickening 
of  the  inner  lip,  particularly  at  its  upper  part,  because 
this  is  never  seen  in  the  last  group.  Our  next  sub-genus, 
Hcmisinus,  has  hitherto  been  placed  with  Melanopsis,  as 
the  base  of  the  aperture  is  notched  :  the  type  is  the  3Ie- 
lania  lineata  *;  in  its  general  form,  indeed,  it  resembles 
the  preceding  shells  ;  but  the  body-whorl,  although  more 
ventricose,  is  yet  contracted  at  its  base,  the  outer  lip  but 
slightly  dilated;  and  the  inner  lip  (now  for  the  first  time 
clearly  developed)  is  complete, —  that  is,  it  extends  from 
one  extremity  of  the  aperture  to  the  other.  The  lip  of 
the  columella,  or  pillar,  instead  of  turning  inw^ard,  turns 
outwards  ;  that  part  which  is  covered  by  the  inner  lip 
being  straight  ;  while  the  sinus,  or  notch,  at  the  base, 
is  even  wider  than  in  Melanopsis,  to  which  this  type 
obviously  leads.  But  before  we  cross  the  threshold  thus 
opened  to  us,  we  must  notice  MeJanella,  —  another  type 
resembling  Hemisiiius  in  shape,  but  having  the  aperture 
perfectly  entire;  the  inner  lip  is  much  developed,  and  its 
upper  angle  has  a  callosity  precisely  like  that  oi  Planaxis. 
So  remarkably,  indeed,  does  one  of  these  Melanellcr  re- 

*  Gray,  in  Griff.  Ciiv.  pi.  13.  fig.  4. 


CHAP.   VII.       MELANIA.  THE    SUB-GENERA.  201 

semble  the  Planaxis  mollis  in  size^  shape,  and  colour  *,  that 
none  but  a  keen-eyed  naturalist  would  know  at  first  which 
was  which.  Both  are  of  the  same  size  and  shape — both 
are  white  —  and  both  are  covered  with  a  pale  fawn- 
coloured  epidermis  ;  the  only  difference  between  them 
being  the  presence  or  absence  of  the  minute  notch  at  the 
base  of  the  pillar.  We  thus  find  the  sub-genera  of 
Melania  not  merely  to  form  a  circle,  but  to  represent, 
in  no  unintelligible  manner,  the  chief  genera  of  the 
sub-family. 

Analogies  of  the  Sub-genera  0/ Melania. 

Sub-geiiera  of  <     ,     •     , /^.         .  Genera  of  the 

Melania.  Analogical  Characters.  Melanianj^. 

Melacantha.  Spire  remarkably  short.  Paludomus, 

Melania.  Spire  persistent,  acute.    Typical.  Melania. 

Potadoma.  [  Spire  obtuse  ;  shell  often  car'-nated  7         Melanopsis. 

i      at  the  suture.     Sub-typical.        J 

r  Body-whorl      veniricose ;      spireo 
Hemisinus.  <     long  ;  base  with  a  wide  but  not  >-         Cerithidea. 

C     a  deep  notch.  j 

tr  t       77  ("Inner  lip  thickened  above;  spire  >         t>,  .»,.„„ 

Melanella.  J     short  or  moderate,  pointed.         j         PLA>fAXis. 

These  remarkable  analogies  result  from  the  breaking  up 
of  the  old  genus  Jfe/aw my  and  this  is  the  best  apology, 
if  any  were  needed,  that  we  can  make  for  so  many  new 
divisions. 

(186.)  The  next  genus,  Melanopsis,  is  no  less  diver- 
sified in  its  minor  types,  so  that  we  may  detect  all  those 
which,  under  a  different  modification,  exist  in  the  last 
genus.  AVe  enter  this  group  by  Melafusus  —  a  name  by 
which  we  designate  a  remarkable  fluviatile  shell,  having 
the  shape  of  a  Fusus  blended  with  that  of  a  Melania  ; 
it  differs  from  Hemisinus  in  having  the  base  more  pro- 
duced, while  the  spire  is  shorter.  Following  this  ap- 
pears the  typical  sub-genus  J/e?a«i«, —  at  once  recognised 
by  its  acutely  pointed  spire  being  longer  than  the  aper- 
ture, the  thick  enamel  at  the  top  of  the  inner  lip,  and 
the  inward  curve  of  the  pillar  :  the  manner  in  which 
the   whorls   are  disposed   on  this    and  the   next    sub- 

*  Sowerby's  Genera,  art.  Planaxis,  fig.  £. 


202  SHELLS    AXD    SHELL-FISH.  PART  I. 

genus   deserves   attention ;     they    are   so  far   imbricate 
that   one   overlaps    the  other  to   full  one  half  of  theii 
length,  so  that  the  suture  of  the   basal  whorl   extends 
half  way  up  that  which   precedes  it,  and   gives  the  ap- 
pearance of  the  outer  lip  ascending  on  the  spire.     But 
among  the  fossils  figured  by  De  Ferussac,  there  are  some 
which  have  an  aspect  altogether   different :  the  spire, 
instead  of  being  acutely  pointed,  is  obtuse,  and  so  short 
as  to  consist  of  only  three  whorls  ;   the  aperture  is  also 
represented  as  much  shorter  than  in  any  of  the  recent 
species,  and  the  base  more  effuse.     Again,  there  are  two 
species  *,  which  perfectly  resemble  the  sub-genera  Me- 
lacantha  and  HemimUra,  being  short,  broad,  and  coro- 
nated with  a  single  row  of  short  spines,  —  the  tip  of  the 
spire  being  acute.     Now,  as   these  two  types  obviously 
accord  with   Potndoma  and  MelacantJia  in   the  adjoin- 
ing circle   of  the    Melanicp,  we     have  not   scrupled   to 
designate  them  as  sub-genera,  —  distinguishing  the  first 
as  Melanithes,  as  being  yet  only  known  in  a  fossil  state, 
and  the  second   as  Canthidomus,  from   its   little  spines. 
The  confidence  we  repose  in  the  accuracy  of  Ferussac's 
beautiful  but  costly  plates,  induces  us  to  do  this  without 
having  ourselves  seen  any  of  these  shells :   but  the  cha- 
racters we  have  stated  cannot  be  doubted ;  and  the  links 
by  which  these  two  presumed  types  are  connected  with 
the  recent  sub-genus  Me/miopsis  are  so  perfect,  that  they 
have  every  indication  of  being  natural  sub-genera,  t  We 
must  now  notice   a  fifth  type,  which  unites  something 
of  the  characters  of  those  two  very  opposite  sub-genera, 
Canthidomus  and  Melafusus ;   this   is   our    sub-genus 
Melatoma,  founded  upon  a  remarkable  Ohio  shell  sent  us 
many  years  ago  by  our  old  friend  professor  Rafinesque. 
It  has  the  general  form  of  a  Pleurotoma  and  of  JMela- 
fusus,  with  a  well-defined  sinus  or  cleft  near  the  top  of 
the  outer  lip  ;  while  the  inner,  though  thin,  is  somewhat 

*  Plate  MelanopsiiUc,  fig.  Ifi.  7.     Plate  <2.  figs.  9,  10. 

t  'I'hus  the  species  at  pi.  2.  fig.  VI.  plainly  connects  Melanttfies  \v\th  Can- 
thidoDius  ;  while  those  on  pi.  I  fig.  14,  15.  seem  to  be  aberrant  to  the  last 
sub-genus,  leading  to  the  long-si)ired  Cerithidia.  Fig.  6.  pl.i2.  is  dearly 
a  Pirena,  and  fig.  8.  a  Cerithiujn. 


CH.  VII.    SUB- GENERA  OF  MELANOPSIS. ANALOGIES.      203 

thickened  above  ;  the  pillar  is  straight^  and  the  notch 
at  the  base  nearly  as  wide  as  that  of  an  ordinary  Pleu- 
rotoma  ;  the  whole  shell  is  marked  with  regular  longi- 
tudinal plaits,  and  coronated  on  the  suture  by  a  row  of 
tubercles.  Our  specimen,  although  in  bad  condition,  is 
still  partially  covered  with  a  brown  epidermis,  beneath 
which  the  shell  is  of  a  livid  colour :  the  aberrant 
species  of  Canthidomus ,  as  C.  costatus  and  Owenii,  pass 
into  Melatoma,  and  complete  the  circle. 

Analogies  of  the  Sub-genera  o/Melanopsis. 

Sub-genora  Sub-genera         Genera 

of  Analogical  Characters.  of  of  the 

Melanopsis.  .  Melania.      Melani4N^. 

Melafusus.  P^^V^'^^rTffir  "''''^'''' ]  ^--«--  Cekithxoe.. 
Melanopsis.  Baseof  the  aperturecontracted.  Potadoma.  Melanopsis. 
Melanithes.        Tip  of  the  spire  obtuse.  Melania.  Melania. 

Cantkiaomus.  [  ^'^V^ort  or  n^od^ra^tf '  ' }  ^lelacantlra.     Pal.bom.s. 
Melato^na.       [^^^^.^^S^^^.^^;""-    '^]Melanella.        Pla.axis. 

I 

The  use  of  the  last,  or  additional  column,  which  con- 
tains the  genera  of  the  entire  sub-family,  is  chiefly 
for  the  purpose  of  showing  that  Melatoma,  while  it 
preserves  its  analogy  to  Pleurotoma,  agrees  also  with 
Planaxis  in  having  the  base  notched,  and  with  Mela- 
nella  by  its  thickened  inner  lip. 

(187.)  The  next  genus  is  that  of  Cerithidea.  We 
have  now  come  to  the  cyclostiform  type,  which,  with 
the  elongate  form  of  Scalaria,  has  an  effuse  and  circular 
aperture,  with  the  outer  lip  dilated  into  a  broad  fringe, 
and  a  very  short  notch  at  the  base.  The  lightness  of 
these  shells  would  seem  to  indicate  that  they  were  flu- 
viatile  ;  but  as  they  are  slightly  variegated,  and  have 
no  epidermis,  we  should  not  be  surprised  at  their  being 
found  in  the  sea, — more  particularly  as  this  appears  to 
be  the  point  where  the  series  of  fluviatile  Testacea 
terminates,  and  the  marine  commences.  Nevertheless, 
the  great  change  from  Melanopsis  to  Cerithidea  is  not 


204 


SHELLS    AND    SHELL-FISH. 


PART  I. 


sudden;   for  it  is  here  we  shall  insert,  as  an  intervening 
form,  our  sub-genus  Ceriphasia  {fig.  38.),  founded  upon 

certain  Ohio   shells  resembling  Ce- 
rithidea,  but  whose  outer  lip  is  thin 
and  sharp.      Unfortunately,  we  can 
find  no  account  of  the  animal,  nor 
are  we  acquainted  with    any  shells 
which  wiU  connect  these  with  3Ie- 
lanopsis  on  one  side,  and.  with  Ce- 
rithidea  on    the    other.     Until  our 
path,   therefore,  is    better    marked, 
we    must    leave    their    precise    situation    as    doubtful. 
There     are    evidently    three    or    four    sub-genera    un- 
discovered   or    uncharacterised,   which   belong    to    this 
genus.     One  of  these,  we  suspect,    will   be  found  in 
certain     small     species,     figured     as  Melanopsides    by 
M.  Ferussac :     their     spire    is    unusually    lengthened ; 
and  the  whorls  are  strongly  and  longitudinally  plaited. 
As  our  last  genus,  we  introduce  Plancijcis, — the  animal 
of    which,    having    been    fully    investigated    and    de- 
scribed by  M.  Quoy,  proves  that  their  shell  must  be 
arranged  with  the  Melaniancs.     It  is  difficult  to  conceive 
why  this  eminent  malacologist  should  have  introduced 
it  near  to  Buccinum,  when  he  expressly  says  that  in  the 
structure  of  the  animal  it  comes  close  to  Melanin.      If 
Planaxis  was  to  be  arranged  from  its  shell  alone,    it 
should  be  placed  next  to  the  Purpurince,  since  it  has 
the  pillar-lip  very  broad  and  flattened  ;   it  is,  in  fact,  a 
Purpura  among  the  MelaniancE,  and,  like  them,  the 
eyes  of  the  animal  are  placed  on  short  peduncles,   close 
to  the  base  of  its  two  long  and  slender  tentacula.    Some 
of  these,  like  the  common  species,  P.  suhsulcata,  has  a 
very   short   spire;    but   another,    the  P.  decoUata,   dis- 
covered by  M.  Quoy,  has  the  spire  of  a  Melanin,  while 
its  name  seems  to  imply  that  the  terminal  whorls  are 
deciduous. 

(188.)  Having  now,  as  far  as  possible,  analysed  this 
sub-family,  a  few  general  remarks  may  follow.  The 
Melauiance  may  be  viewed  as  that  group  of  the  Tur- 


CHAP.    VII.     MELANIAN^. GENERAL    RE3IARKS.  205 

hidce  which  stand  upon  the  very  confines  of  the  phyto- 
phagous circle,  yet  still  within  its  limits :  it  therefore 
partakes  much  more  of  the  tribe  which  Nature  is  about 
to  enter  upon,  than  of  that  she  is  on  the  point  of  quitting; 
and,  consequently,  not  only  the  animal,  but  even  the 
shell,  is  so  fashioned  as  to  exhibit  this  preponderance  to 
the  first  rather  than  to  the  last  group.  On  this  broad 
principle  do  w^e  account  for  the  indication  of  a  basal 
channel  seen  in  all  the  sub-genera  of  Melanopsis,  in  Pla- 
naxis,  and  in  Cerithidea.  Nay,  to  such  a  refined  point 
is  this  principle  of  gradual  developement  carried,  that 
we  hardly  know,  at  present,  where  to  draw  a  line  of 
demarcation  between  the  TurhidcB  and  the  Stromhidcp ; 
not,  of  course,  in  their  pre-eminent  types,  but  in  those 
which  are  aberrant.  Cerifhiion  is  in  one,  and  Ceri- 
thidea in  the  other.  Their  typical  forms  are  easily  dis- 
tinguished. But  in  which  of  these  are  we  to  place  the 
apparently  anomalous  sub-genus  Cerlphasia  ?  and  how 
delicate  and  refined  are  the  characters  by  which  this  is 
proposed  to  be  detached  from  the  fiuviatile  PotomidcB  of 
Brongniart !  It  is  here,  then,  rather  than  among  any 
other  of  the  Melaniance,  that  we  should  say  the  tw^o 
tribes  actually  unite.  All  modern  writers,  indeed,  have 
perceived  this ;  and  some  have  gone  so  far  as  to  unite 
all  the  sub-genera  of  Melania  and  Melanopsis,  and 
many  of  the  CerithincE,  into  one  genus.  It  is  quite 
clear,  however,  that  if  this  principle  be  acted  upon,  the 
greater  our  knowledge  of  the  Testacea  is  enlarged,  the 
more  must  the  number  of  our  genera  or  divisions  —  call 
them  what  we  will  —  be  reduced.  New  species  bring 
new  modifications  of  forms  ;  and  these,  filling  up  inter- 
vals, and  softening  down  differences,  wnll  so  blend  groups 
which  are  noAv  in  some  degree  detached,  that  the  whole, 
in  process  of  time,  will  present  but  one  continued  chain 
of  gentle  gradations.  No  "  well-marked  divisions,"  in 
the  sense  which  the  term  has  been  used  in,  could  by 
any  possibility  exist.  Our  tribes  and  families,  genera 
and  sub-genera,  v/ould  melt,  one  after  the  other,  into 
the  general  mass  —  they  would  be  abolished  —  and  our 


206  SHELLS    AND    SHELL-FISH.  PART  I. 

divisions  would  be  species,  and  species  only.  We  may 
be  pardoned,  perhaps,  for  alluding  to  this  great  error  in 
our  nomenclature  more  than  once,  because  it  appears  to 
us  to  be  fraught  with  more  inconveniences  —  not  to  say 
evils  —  than  those  of  an  opposite  nature  ;  and  because,  in 
the  group  now  before  us,  we  have  been  obliged  to  name 
and  define  so  many  new  divisions.  These  divisions,  in 
fact,  will  show  more  forcibly  than  any  general  argu- 
ments, the  perfect  confusion  in  which  we  must  have 
exhibited  this  portion  of  the  Testacea,if  we  had  left  them 
under  the  three  or  four  genera  where  they  now  stand  in 
the  latest  systems  of  conchology. 

(189-)  That  the  TarhincB  follow  the  Melaniance  is 
evident  from  the  close  connection  of  Cerithidea  Sw. 
with  Scalar ia  Lam.  :  the  little  basal  channel  of  the  former 
gradually  lessens  in  the  aberrant  species,  until,  in  one  we 
possess  from  Florida,  it  is  a  mere  vestige.  This  affinity 
fixes  the  station  of  the  sub-family  before  us  better  than  all 
theoretical  reasons.  The  Turbince  are  all  marine  shells, 
and  possess  a  perfectly  entire  aperture.  Their  typical 
genus,  Turritella,  is  subulate,  or  awl-shaped,  so  as  to  have 
the  spire  very  long.  All  the  TurhincB  have  their  aper- 
ture closed  by  an  operculum,  and  their  substance  is  never 
perlaceous.  From  overlooking  this  very  obvious  differ- 
ence, even  in  the  shells,  all  conchologists,  excepting  Hum- 
phrey, have  blended  them  with  the  Trocliidce.  Cuvier,  at 
least,  from  the  know^ledge  he  had  of  the  difference  of  the 
animals,  should  have  not  fallen  into  this  error :  the  con- 
fusion has  been  still  further  increased  by  M.  Ferussac  ;  for 
he  has  given  to  the  Turbines  of  Humphrey  the  new  name 
of  Littorina,  and  transfers  that  of  Turbo*  io  Humphrey's 
Senectus.  We  do  not  usually  trouble  the  reader  with  these 
misnomers,  but  we  shall  correct  them  as  they  occur.  Our 
genus  Turbo,  therefore,  is  that  of  Linmcus  and  Hum- 
phrey, the  last  of  whom  we  also  follow  in  placing  all  the 
perlaceous  ones  in  that  of  Senectus.  There  are  so  few 
variations  or  sub- genera  in  the  Turbine,  that  we  shall 

*  The  common  winkle,  Turbo  Uttoreus  Linn.,  is  the  type. 


CHAP.    VII.  GENERA    OF    THE    TURBINiE.  207 

here  chiefly  confine  our  notices  to  the  five  leading  genera  : 
these  appear  to  be  Scalaria  Lam.,  Turritella  Lam.,  Turbo 
Humph.,  Melampus  Mont.,  and  Scissurella  D'Orbigny. 
(190')  The  genus  Scalaria,  as  the  circular-mouthed 
group,  represents  Cyclostoma :  the  typical  form  seen  in 
the  common  wentletrap  (^S".  pretiosa  Lam.)  has  no  pillar, 
although  it  is  a  long  spiral  shell.  These  lead  obviously  to 
Turritella,  where  the  shell  is  even  more  attenuated,  so  that 
the  whorls  are  fully  as  numerous  as  in  Terehra,  which  it  thus 
represents.    Turbo  (^pulchra,fig.  39.)  is  the  next  genus, 

differing  chiefly,  as  regards  the  shell, 
in  the  inner  lip  being  broad  and  flat- 
tened, and  the  spire  often  very  short, 
or  not  longer  than  the  aperture. 
There  is  certainly  a  resemblance  be- 
tween many  of  these  shells  and  the 
more  globose  Trochida;,  particularly 
the  sub-genera  Pagodella  and  Echi- 
nella,  which  are  not  perlaceous  ;  but 
the  great  thickness  and  depression 
of  the  pillar  in  Turbo,  its  perfectly  round  aperture,  and 
the  convexity  of  the  body-w^horl,  are  sure  marks  of  dis- 
tinction. In  the  invaluable  plates  of  M.  Quoy,  there  is 
a  figure  of  the  animal  of  a  species  of  Turbo  (under  the 
name  of  Littorirui),  which  shows  it  to  have  almost  a 
zoophagous  structure,  —  so  totally  different  indeed  from 
that  of  Trochus,  that  they  have  even  no  analogy  to  each 
other.  The  same  may  be  said  of  PhasianeUa,  which  is 
only  a  long-spired  Trochus,  analogous,  indeed,  to  Tur- 
ritella, but  with  the  short  mouth  and  lateral  filaments  of 
the  TrochidcB. 

(191-)  The  next  genus,  Melampus  Montf.,  is  one  of 
particular  interest.  It  was  originally  proposed  by  Lamarck; 
but  upon  being  told  that  they  were  land  shells,  he  aban- 
doned his  name  ofConovulus,  and  incorporated  the  species 
in  his  genus  Auricula.  This  was  clearly  a  retrograde 
movement ;  for,  even  had  his  information  been  correct,  the 
difference  of  these  two  genera  on  one  hand,  and  the  close 
resemblance  between  Tornatella  smd Melampus,  is  too  ob- 


208  SHELLS    AND    SHELL- FISH.  PART   I. 

vious  to  be  overlooked.  From  the  MS.  notes  of  Guildifg, 
it  appears  that  these  little  shells  are  not  more  terrestrial 
than  the  other  marine  TurhincB.  In  regard  to  amphibious 
Testacea,  or  such  as  live  both  in  and  out  of  water,  the 
following  valuable  remarks  are  taken  from  the  Guilding 
MSS.  "  The  genus  Melampus  commonly  inhabits  the 
shallow  parts  of  the  coasts,  but  I  have  receiNedi  Melaynpus 
coniformis  }  from  stagnant  fresh  waters  on  the  shores  of 
Tortola,  which  only  communicate  with  the  sea  occasion- 
ally during  heavy  rains,  when  the  accumulated  water  is 
discharged  with  it.  They  are  found  creeping  on  the 
mangrove  roots ;  and,  like  manyof  the  NeritidcB  and  Tur~ 
hinidce,  are  perfectly  amphibious,  and  very  tenacious  of 
life.  The  latter,  indeed,  though  they  descend  to  feed  at 
night,  are  often  seen  on  the  trees  of  the  coasts,  and  on  the 
dark  black  rocks  elevated  above  the  surface  at  high  water ; 
they  remain  stationary  on  the  latter  during  the  hottest 
hours,  even  when  it  is  painful  to  walk  on  them  from 
their  great  heat.  The  difference  of  the  waters  inhabited 
by  testaceous  Mollusca  does  not,  as  was  once  supposed, 
offer  a  certain  guide  for  the  division  of  genera.  Many 
of  the  JVeritince,  for  instance,  dwell  in  the  fresh  waters 
of  rivers,  while  I  have  dredged  up  others  in  the  bays  and 
shallows  of  the  ocean."  * 

( 1 92.)  This  genus,  as  far  as  we  Cvin  at  present  judge, 
seems  to  be  composed  of  the  following  groups :  —  Geo- 
vula  Sw.,  Melampus  Montf.,  Rhodostoma  Sw.,  Pedipes 
Adanson,  and  Scarabus  Montf.  All  these  are  clearly 
separated  from  the  sub-genera  of  Turbo  by  the  total 
want  of  an  operculum  ;  while  from  Auricula  they  are 
still  further  removed  by  the  branchia  being  pectinated, 
by  having  two  tentacula,  with  the  eyes  at  the  base,  or 
sessile,  and  in  the  shells  being  more  solid.  The  highly 
interesting  and  valuable  essay  by  Mr.  Lowe  on  Pedipes 
and  Melampus  t,  satisfactorily  proves  that  these  cannot 
belong  to  the  Pulmonaria  of  Cuvier,  and  are  therefore 
excluded  from  the  lanl  shells,  or  HcUcidce.  But 
whether  the  genera  Geovula  and  Scarabus  have  their 

«  Guilding's  MSS.  f  Zool.  Jourii  No.  xix.  p.281. 


CHAP.   VII.  MELAMPUS.  —  SCISSURELLA.  209 

branchia  also  pectiniform,  we  have  no  means  of  knowing. 
The  aspect  of  their  shells,  however,  induces  me  to  place 
them  for  the  present  in  the  same  group,  more  especially 
since  we  have  already  shown  they  would  altogether  dis- 
turb what  we  think  is  the  natural  series  of  Auricula  and 
Clausilia.  We  do  not  attach  any  importance  to  the  fact 
of  Geovula  having  an  epidermis,  because,  although  the 
excellent  zoologist  just  named  thought  otherwise,  we 
possess  several  specimens  of  a  typical  West  Indian  Me- 
lampus,  where  a  thin  brown  epidermis  is  over  the  whole 
shell ;  and  this  also  is  common  to  the  sub-genus  Rhodo- 
stoma.  The  peculiar  depression  of  the  numerous  whorls 
of  the  spire  in  Geovula,  Scarahus,  Melampus,  and  Rho- 
dostoma,  strikingly  contrasts  again  with  the  few  and 
produced  volutions  of  the  true  Auriculce  ;  and  the  whole 
are  separated  from  Tornatella,  by  the  animal  of  the  latter 
having  an  operculum,  and  being  differently  formed.  Tor- 
natella, in  fact,  seems  to  represent  the  sub-genus  3fe- 
lampus  ;  while  Truncatella  of  Lowe,  probably^  does  the 
same  in  the  circle  of  Turritella.  The  whole  of  this 
sub-family,  however,  requires  much  more  attention  than 
we  have  yet  been  able  to  give  it. 

(193.)  We  place  the  genus  Scissurella  as  the  only 
type  of  our  last  division,  from  a  belief  that  it  is  analogous 
to  lanthina.  It  was  first  characterised  by  M.  D'Orbigny, 
one  of  the  most  eminent  naturalists  of  France,  who  found 
his  specimens  among  sea  sand.  It  is  very  minute,  and 
the  animal  is  unknown  :  its  general  shape  is  that  of  Si- 
gnretus  or  Vitrina,  but  there  is  the  same  sort  of  long 
narrow  slit  in  the  outer  lip  as  is  seen  in  the  Pleuroto- 
mince,  m  Plevrotoivaria,  and  m  lanthina;  thus  we  have 
numerous  analogies,  while  in  affinity  we  consider  this 
genus  to  be  the  patelliform  type  of  the  TurhincE.  The 
very  beautiful  figures  in  Mr.  Sowerby's  Genera,  is  all 
we  yet  know  of  Scissurella;  but  we  possess  two  or  three 
similar  shaped  shells,  which  appear  closely  connected  to 
this  type,  and  probably  enter  into  the  same  genus. 

(194.)  We  shall  now  take  a  rapid  view  of  the  five 
genera  which  appear  to  compose  the  sub-family  before  us. 

p 


210  SHELLS    AND    SHELL-FISH.  PART  I. 

These  and  their  analogies  may  be  arranged  in   the  fol- 
lowing table  :  — 

Analogies  of  the  Turbine. 

Genera  Sub-families  Genera 

of  the  Analogies.  of  the  of  the 

TuRBiN^E.  Turbid^.       Melanianje. 

TORBO.  [^P^hl^rhlTpe'^rrL^''"^"]  AMPULLARiN*:.    Melanopsis. 

TtiRRiTELLA.       Spire  excessively  long.  Melanian^.       Melania. 

ScALARiA.  Mouth  circular,  margined.      Turbinje.  Cerithidea. 

ScissuRELLA.    f^P^':'"'',^     ^'^^^  ^^""'^ '■'\u^Tm^M.  Plumxis. 

(3i^iaavK.cM,ua..    ^     outer  lip  sinuated.  3 

Melampus.       {^sh^rt^^"''"'^'  '^"^  ''^•"^JThallicera.       Paludomus. 

We  introduce  two  series  of  analogies  in  this  table, 
because  one  will  better  illustrate  what  may  be  thought 
obscure  in  the  other.  The  two  first  set  of  analogies. 
Turbo  and  Turritella,  are  particularly  strong;  for  we  thus 
find  the  needle-like  Melanianje  represented  by  Turritella, 
and  Turbo  by  Ampullaria,  both  equally  ventricose  and 
turbinate.  The  thick  or  margined  aperture,  again,  of 
Scalaria  and  Cerithidea  exist  in  no  other  groups.  It 
must  be  remembered,  also,  that  the  Turbidte,  as  a  family, 
is  the  cyclostiform  or  circular-mouthed  group  of  the 
phytophagous  tribe  ;  and  this  character  runs  through  the 
whole  group,  with  the  exception  of  Melampus  :  Scis- 
surella  and  lanthina  have  the  strongest  analogy ;  and 
these,  with  Planaxis,  have  the  most  effuse  apertures  of 
all  their  congeners.  AVe  must  confess,  indeed,  that,  but 
for  the  discovery  of  Scissurella,  we  had  long  imagined 
that  Planaxis  formed  the  most  aberrant  genus  of  the 
Tnrbince.  The  last  set  of  analogies  is  those  between 
Melampus,  Thallicera,  and  Paludomus:  it  is  not  very 
strong  ;  yet,  as  they  are  the  only  shells  with  plaits  on 
the  pillar,  they  represent  the  volutes  and  the  land  Auri- 
culae; while  it  seems  that  JMr.  Say  has  discovered  an 
Anculosa,  whose  pillar  bears  a  plate  or  fold  precisely 
analogous  to  that  in  Thallicera. 

(195.)     Of  the  next  sub-family,  represented  by  the 
beautiful  and  delicate  lanthince,  or  oceanic  snails,  little 


CHAP.   VII.  TURBINE.  TROCHIDiE.  211 

can  be  said.  The  only  two  genera  we  can  venture  to 
place  in  it  are  lanthina  of  Lamarck  and  Trichopodus  of 
Sowerby.  The  first  consists  of  those  pretty  but  fragile 
violet  and  white  snails  which  so  much  resemble  the  He- 
licidcE  :  the  animal  has  been  described  by  Cuvicr,  and  is 
so  very  peculiar,  that  it  cannot  be  arranged  in  any  of 
the  foregoing  divisions,  and  yet  it  occupies  that  place  in 
the  Regne  Animal  precisely  where  we  should  have  placed 
it,  —  that  is,  immediately  after  Melampits.  "  Theanimal," 
observes  Cuvier*,  "has  no  operculum;  but  the  under  sur- 
face of  its  foot  is  furnished  with  a  vesicular  organ,  resem- 
bling a  bubble  of  foam,  but  composed  of  a  solid  substance, 
which  prevents  the  animal  from  crawling,  yet  allows  it 
to  float  on  the  surface  of  the  water.  The  head,  a  cylin- 
drical proboscis,  terminated  by  a  vertically  cleft  moutli, 
and  armed  wdth  little  hooks,  has  a  bifurcated  tentaculum 
on  each  side."  Nothing,  unluckily,  is  here  said  of  the 
position  of  the  eyes;  but  it  is  sufficiently  clear  from  this 
short  account,  and  also  from  the  shell,  that  the  lanthince 
belong  to  the  family  before  us.  We  follow  Lesson  in 
placing  the  singular  genus  TricJiopodus  as  intermediate 
between  this  and  the  last  division,  yet  coming  much 
nearer  to  lanthina  than  to  Turbo.  This  brings  us  to  the 
end  of  the  series;  and  if,  as  w^e  believe,  ThaUicera  stands 
between  lanthina  aLndAmpuUaria,  we  reach  again  the 
point  from  whence  we  commenced  our  survey,  and 
thus  complete  the  entire  circle  of  the  Turbid^. 

(196.)  The  TrochidjE,  as  a  family,  are  distin- 
guished from  all  the  phytophagous  Testaoea,  both  by 
their  animals  and  their  shells  ;  although  much  more 
by  the  former  than  by  the  latter.  The  invaluable  re- 
searches prosecuted  by  the  French  voyagers,  more  es- 
pecially by  MM,  Quoy  and  Gaimard,  joined  to  the 
scattered  notices  in  other  authors,  have  so  far  afforded 
information  on  the  animals  of  the  Trochid^,  as  to 
detach  them  from  the  Turbidcp,  with  which  concho- 
logists    have    hitherto    mixed    them.     The    following 

*  Griff.  Cuv.  xii.  63. 

p  2 


212  SHELLS    AND    SHELL-FISH.  PART  1. 

analysis   may,    therefore,  be  interesting,    as    the  most 
perfect  we  have  been  able  to  lay  before  the  reader. 

(197.)  The  animals  of  the  present  family  widely 
differ,  both  in  habits,  shape,  and  anatomy,  from  those 
inhabiting  the  TnrbidfP.  In  the  first  place,  their  mouth 
is  mor&  like  that  of  the  slugs  and  snails  (^Helicidcp), 
being  composed  of  two  short  lips, — the  upper,  and  some- 
times the  under,  of  which  is  cleft  and  fringed  ;  the 
eyes,  instead  of  being  supported,  as  in  the  Turbid fP,  half 
^vay  on  the  tentacula,  are  seated  on  two  short  but  very 
thick  tubercles  ;  while  the  long  and  slender  tentacula 
are  nearly  cylindrical,  and  of  equal  breadth  throughout  : 
the  Avhole  structure,  in  short,  is  intermediate  between 
the  animals  of  the  ear-shells  (^Haliotidce)  and  the 
?  lails  (^Helicidce^  ;  further,  the  generality  have  three 
long  slender  filaments  on  each  side  of  the  foot,  as  long 
as  the  tentacula,  but  the  use  of  which  is  unknown.  In 
one  of  the  typical  groups,  and  in  PhasmiieUa,  the 
aperture  is  closed  by  a  strong,  and  often  very  thick, 
shelly  operculum  ;  but  in  the  Trochidce,  this  covering 
is  horny,  except  in  that  particular  group  which  con- 
nects them  with  the  Senectince  :  in  the  Rofellince,  again, 
the  operculum  is  horny. 

(198.)  The  shells,  in  their  typical  examples,  may  in 
general  be  recognised  both  by  their  pyramidical  shape, 
and  by  theh-  substance  being  perlaceous, — a  fact  always 
indicated  by  the  rich  pearly  hue  of  the  aperture.  As 
this  is  the  most  prevalent,  it  is  perhaps  the  best  cha- 
racter for  the  mere  conchologist  to  go  by  :  and  yet  this 
will  not  serve  in  all  cases,  because  the  pheasant -snails 
(^Phasiianella  Lam.)  and  the  carriers  (Onustiis  Hump.) 
are  not  pearly  ;  and  even  the  most  aberrant  sub-genera 
in  Senectus,  Trorhtis,  and  Monodonta,  which  represent 
the  carriers,  are  equally  destitute  of  this  substance. 
Nevertheless,  all  these,  excepting  the  first,  have  their 
basal  whorl  so  much  depressed  or  flattened,  and  their 
shape  so  trochiform,  that  a  little  attention  will  soon 
make  the  student  familiar  with  them. 

(199-)   ^^  e  think  the  following  groups  are  the  pri- 


CHAP.   VII.      TROCHIDyE.  PRIMARY    DIVISIONS.  21 


n 


mary  divisions^  and  hold  the  rank  of  sub-families  : 
—  1.  The  Phasianellin^,  Lam.,  where  the  shell  is 
spiral  and  obovate,  and  shaped  like  a  Butimus ;  the 
outside  is  polished,  and  the  operculum  shelly.  2.  The 
Senectin^*,  or  sea  snails,  resembling  the  garden  snail 
in  form,  but  perlaceous,  and  furnished  with  a  thick, 
round,  shelly  operculum.  3.  The  Trochin^,  or  tro- 
chuses,  having  the  shape  more  pyramidical,  the  body- 
whorl  flattened,  and  the  aperture  closed  by  a  horny 
operculum.  4.  The  Rotellin^,  or  wheel-shells, 
which  are  also  perlaceous,  and  nearly  discoid  in  shape, 
with  a  thickened  mass  over  the  inner  lip.  5.  Pleuro- 
TOMARiA  Tief.,  —  a  fossil  trochiform  shell,  having  a 
slit  on  the  outer  lip,  as  in  the  genus  Pleurotoma 
of  Lamarck.  Such  are  the  primary  forms,  which 
seem  to  belong  to  the  TROcniDiE.  Our  information 
on  the  animals  is  partial  ;  but  there  is  enough  to 
guide  us  in  three  of  the  chief  groups.  Thus  the  ques- 
tion whether  Phasianella  belongs  to  this  family  or  the 
TurhidcB  has  been  set  at  rest  by  M.  Quoy,  among 
whose  beautiful  figures  is  the  animal  of  the  typical 
species  :  the  same  eminent  zoologist  has  also  decided 
the  relations  of  Senectus  to  the  TrochincB,  by  figuring 
the  Turbo  sarmaticus,  —  thus  showing  its  affinity  to 
the  animal  of  Trochus.  The  gradual  chain  of  con- 
nection between  Trochus,  Solarium,  and  Rotella,  leaves 
us  in  no  doubt  that  these  also  form  part  of  the  family ; 
but  whether  Pleurotomaria  is  merely  a  genus  of  the 
latter  group,  or  the  representative  of  a  sub-family, 
must  still  remain  a  disputed  point.  We  insert  it,  how- 
ever, under  the  latter  supposition,  because  it  will  appear 
by  the  following  analysis,  that  it  can  in  no  wise  be  in- 
corporated elsewhere. 

(200.)  The  Phasianellinj=;,  or  pheasant-snails, 
form  one  of  the  most  isolated  genera  in  the  whole  of 
the  Testacea.  That  they  represent  the  TurbidcE,  is 
obvious ;    for  Lamarck  and  his  followers  have  mixed 

*  Senectus  of  Humphrey,   Marmarostoyna  (pars)  Sw.,  Turba  of  Cu- 
vier,  &c. 

p  3 


^I4f  SHELLS    AND    SHELL-FISH.  PARTI. 

them  together.  Their  exterior  is  the  most  beautiful  of 
all  the  Trochidce,  not  merely  by  the  richness  and  end- 
less variety  of  their  colours,  but  from  their  exterior 
being  almost  as  highly  polished  as  the  olives.  The 
mouth  has  two  cleft  and  crenated  lips  ;  the  tentacula  are 
long,  slender,  and  of  equal  thickness  throughout,  while 
on  each  side  of  the  body  are  three  lengthened  filaments. 
The  PhasianellcB  are  nearly  all  natives  of  the  Pacific 
Ocean,  and  have  an  oval-shaped  operculum.  One 
species,  of  a  small  size,  is  found  in  Britain.  This  is 
obviously  the  long-spired  group  of  the  Trochidcp,  re- 
presenting in  this  family  the  Turhidce,  the  Buccinidcs 
(wherein  is  Terebra),  and  the  CerithincB. 

(201.)  The  Senectin^,  or  snake-shells,  were  sepa- 
rated by  Humphrey  from  the  Linnsean  genus  Turbo 
near  forty  years  ago  ;  but  conchologists  have  continued, 
up  to  this  day,  to  confound  the  two,  or,  rather,  to  mis- 
apply their  names.  This  most  natural  group  contains 
nearly  all  the  largest  and  the  most  splendid  shells  of 
the  family,  —  all  of  which  we  believe,  possess  a  circular 
and  very  strong  stony  operculum.*  The  body-whorl 
is  always  ventricose,  and  is  not  depressed,  like  that  of 
the  TrochincB ;  it  is  produced  at  its  base,  in  the  typical 
examples,  into  an  obtuse  lobe,  analogous  to  the  prolong- 
ation of  the  base  of  the  zoophagous  gastropods,  yet 
without  any  channel.  Thus  we  perceive,  at  every  step, 
how  completely  Nature  preserves  her  uniform  principles 
of  representation  ;  for  it  is  clear  that  these  Senectmce 
represent  the  zoophagous  or  channeled  tribe,  just  as 
Trochus  represents  the  Phytophnga.  The  snake-shells 
form  themselves  into  very  natural  genera.  The  first,  to 
which  we  retain  the  sub-family  name  of  Senectus,  is 
known  by  the  spire,  although  small  and  short,  being 
always  ventricose  and  pointed,  the  body-whorl  very 
large,  the  base  produced  into  a  lobe,  and  the  umbilicus 
altogether  wanting.  The  most  gigantic,  elegant,  and 
magnificent  shells  of  the  whole  family  enter  into  this 
group,  which  are  chiefly  natives  of  the  southern  hemi- 

*  Excepting,  perhaps,  that  type  which  corresponds  to  Onustus  Huinph. 


CHAP.  VII.  TROCHID^,  SENECTIN^.  215 

sphere.  The  ventricose  form  of  the  body-whorl  of, 
course,  modifies  the  shape  of  the  aperture,  which  is  thus 
always  circular,  and  but  seldom  oblique.  Before  we 
had  sufficiently  studied  this  family,  we  included  the 
foregoing  in  our  genus  Marmarostoma ;  but  we  intend 
to  limit  that  name  to  the  umbilicated  division  of  Hum- 
phrey's Senectus,  represented  by  the  M.  versicolor* ,  — 
the  passage  from  one  to  the  other  group  being  made  by 
our  Senectus  co?'onatus.f  The  umbilicus  in  these  is, 
indeed,  small,  but  very  deep ;  the  spire  is  ahnost  perfectly 
flattened,  the  tip  obtuse,  and  the  base  even  more  pro- 
duced than  in  Senectus.  It  is  quite  clear  to  us,  that 
more  than  one  species  is  confounded  by  conchologists 
under  the  specific  name  of  coronatus;  since  some  have 
an  umbilicus,  and  others  not.  In  all  the  Marmaro- 
stomce,  however,  the  pillar  is  present ;  but  on  entering 
upon  Lamarck's  Delphinula,  the  umbilicus  is  open  to 
the  terminal  spiral  whorl,  and  there  is  no  pillar  :  the 
Turbo  torquatus  of  the  old  conchologists  is,  therefore, 
a  true  Delphinula,  connecting  this  genus  with  the  last. 
Of  the  fossil  shells  referred  to  Delphinula  we  shaU  not 
speak  ;  judging  from  their  figures,  and  from  a  few  speci- 
mens we  possess,  they  appear  to  require  a  thorough 
revision,  and  to  contain  types  very  different  from  those 
which  are  recent.  Our  next  genus,  if  it  be  really  one, 
contains,  at  present,  but  two  species,  differing  in  being 
very  slightly  perlaceous ;  they  may  be  compared  to 
Delphinulce  without  an  umbihcus.  The  name  of  Cyclo- 
cantha  may  explain  their  round  form,  and  the  circle  of 
spines  on  the  body- whorl.  Cidaris  is  the  last  genus, 
and  contains  those  Senecti  which  have  the  base  desti- 
tute of  any  lobe,  the  aperture  more  oblique,  the  apex 
of  the  spire  obtuse,  and  the  outer  surface  almost  always 
smooth;}:;  the  aperture  is  quite  circular,  and  closed  by 
a  thick  calcareous  operculum.  There  are  many  species, 
of    which    the    beautiful  Cidaris  sarmaticus   may  be 

*  Turbo  versicolor  Martini,  pi.  176.  fig.  ITIO,  1741. 
t  Ency.  Meth.  448.  fig.  2. 

%  Except  in  our  S.  coronata,  which  connects  this  sub-family  with  the. 
next. 

P    4 


2l6  SHELLS    AND    SHELL-FISH.  PARTI. 

selected  as  the  most  typical.  By  simply  following  the 
line  of  affinity,  we  thus  return  to  our  first  genus,  Se-- 
nectus;  for  it  is  easy  to  perceive  that  Cidaris  pethiolatus 
has  the  spire  and  general  aspect  of  Senectus,  with  the 
truncated  base  and  smooth  surface  of  Cidaris.  The 
circle,  in  short,  is  complete. 

(202.)  The  TRocniNiE  naturally  follows  the  last 
division.  The  body-whorl,  which  in  the  snake-shells 
is  ventricose,  is  here  depressed,  and  often  flattened 
beneath ;  and  this  modifies  the  aperture,  which  thus 
becomes  broader  than  it  is  high,  or  transversely 
oval.  It  is  by  these  latter  characters,  also,  that  the 
TrochidcB  are  separated  from  the  Turbidce,  -where  the 
aperture  is  invariably  either  round  or  longitudinally 
oval.  In  the  last  genus  of  the  Senectince,  nature 
has  begun  to  indicate  the  change  from  a  round  to  a 
transverse  aperture.  The  operculum  of  all  the  more 
typical  forms  of  the  Trochida  is  horny ;  but  this  change 
is  eflfected  gradually.  The  first  genus,  consequently, 
of  the  Ti'OchiniE  combines  the  characters  of  both  sub- 
families, Canthorhis,  in  fact,  has  the  depressed  aper- 
ture of  the  TrochincE,  with  the  shelly  operculum  of  the 
Senectina.  Canthorhis  is  a  remarkably  diversified  group : 
it  contains  the  largest  of  the  Trochi,  properly  so  called, 
as  distinguished  from  Senectus  ;  but  in  all  the  shell  is 
Highly  perlaceous,  the  aperture  transversely  oval,  and 
the  operculum  shelly.*  The  five  types  of  form,  or  sub- 
genera, are  all  recent;  and  as  their  characters  will 
subsequently  be  given,  we  shall  only,  in  this  place,  il- 
lustrate them  by  general  observations.  All  the  large, 
spinous,  nodulous,  and  long-spired  Troehi  belong  to 
this  genus,  in  which  there  are  very  few  having  a  smooth 
surface.  It  is  connected  to  Cidaris  by  Riigosus  and 
Cookii;  to  Onustus  by  the  sun-shells  ;  and  to  the  typical 
Troehi  by  our  sub-genus  Carinidea,  into  which,  as  we 
suspect,  will  enter  the  Troehus  Niloticus  of  Linnaeus, — 

*  If,  as  Sowerby  mentions,  the  operculum  of  the  Troehus  NilotiaiS  is 
hornv.  instead  of  shHly,  it  will  be  the  osculant  species  connecting  Can- 
ihorbis  to  our  genus  Troehus. 


CHAP.  VII.  TROCHIN^. THE    GENERA.  21? 

a  very  remarkable  shell :  out  of  hundreds,  we  have 
never  yet  seen  a  specimen,  however  large,  which  had  a 
perfectly  formed  mouth,  so  that  we  feel  somewhat  un- 
decided as  to  its  precise  station.  In  a  young  state,  the 
basal  volution  is  often  perfectly  flat,  and  even  concave ; 
and  this  gives  the  margin  precisely  the  same  carinated 
edge  as  belongs  to  Carinidm  ;  but  when  more  advanced 
it  becomes  convex,  as  in  the  genuine  TrocM,  —  thus 
uniting,  at  different  periods  of  its  growth,  the  characters 
of  the  two  groups  between  which  it  appears  to  stand. 

(203.)  Having  now  shown,  by  the  foregoing  details, 
the  union  of  the  Senectince  and  the  TrochincB,  we 
shall  briefly  characterise  the  remaining  genera  of  the 
sub-family  we  are  now  upon,  and  then  notice  their  sub- 
genera. Canthorbis  has  already  been  defined :  following 
this  is  Trochus,  properly  so  called,  where  the  umbil- 
icus, if  it  exists,  is  never  toothed,  and  very  rarely 
channeled.  In  Monodonta,  these  characters  are  reversed; 
the  umbilicus,  if  present,  is  always  either  toothed  or 
channeled,  and  the  aperture  striated.  The  fourth  genus 
is  Solarium,  where  the  umbilicus  is  so  large  as  to  reach 
to  the  apex,  the  pillar  is  absent,  the  shell  nearly  dis- 
coid, and  the  aperture  without  any  defined  lip.  The 
last  genus  is  Onustus,  long  ago  separated  by  Humphrey, 
to  include  those  singular  and  half-formed  shells,  called 
by  collectors.  Carriers.  Of  the  animals  by  which  these 
are  formed,  we  as  yet  know  nothing  ;  but  their  shells  are 
composed  partly  of  the  usual  calcareous  substance,  and 
partly  of  little  stones  or  fragments  of  other  shells, 
which  the  animal  gathers  up  and  incorporates  on  the 
outer  surface  of  its  own  habitation.  A  gradual  series 
of  intervening  forms  unites  this  group  on  one  hand  to 
Solarium,  and  on  the  other  to  Canthorbis  ;  so  that  the 
whole  of  the  TrochincB,  being  united  into  one  circle, 
constitute  a  natural  and  perfect  group.  We  shall  now 
notice  each  of  these  genera  in  detail. 

(204.)  Having  already  spoken  of  Canthorbis,  we 
pass  to  the  second  genus,  Trochus.  Were  we  to 
make  this  an  artificial  group,  its  definition  would  be  very 


218 


SHELLS    AND    SHELL-FISH.  PART  I. 


easy,  for  it  might  then  be  formed  to  contain  all  those 
small  or  moderately  sized  trochuses,  which  are  without 
a  distinct  tooth  at  the  end  of  the  pillar,  and  have  a  horny 
operculum.  But  this  definition  would  break  up  the 
natural  series.  The  group,  in  fact,  is  so  difficult  to  cha- 
racterise in  general  terms,  that  we  suspect  its  funda- 
mental difference  from  that  of  Monodonta  lies  in  certain 
peculiarities  of  the  animals,  with  which  at  present  we  are 
unacquainted ;  but  if,  to  the  foregoing  characters  of 
Trochus,  we  add  that  one  of  its  sub-genera  has  a  promi- 
nent tooth,  but  no  umbilicus,  and  that  another  is  not  per- 
laceous,  we  shall  then  name  the  only  exceptions.  The 
whole  genus,  then,  divides  itself  into  the  following  five 
sub-genera:  —  1.  Chlorostoma,  where  the  basal  volution  is 
either  perfectly  flat  or  concave,  the  margin  carinated,  and 
the  outer  lip  so  oblique  that  it  extends  half  way  round 
the  circumference  of  the  shell ;  the  umbilicus  is  very 
deep,  and  is  bordered  on  one  side  by  the  inner  lip, 
which  is  suddenly  truncate  as  soon  as  it  reaches  half 
way  round  the  umbilicus  :  this  leads  to  Troclius,  or  the 
typical  sub-genus.  All  our  British  species,  excepting 
T.  zizyphinus,  come  into  this  division  ;  the  umbilicus 
is  more  or  less  deep,  and  the  aperture  either  entire  or 
with  a  very  slight  angle  at  the  piUar :  by  degrees, 
however,  this  angle  is  so  much  developed,  that  it  assumes 
the  appearance  of  a  tooth  :  thus  we  are  led  into  the  sub- 
genus Trochidon,  nearly  all  of  which  are  natives  of  the 
southern  hemisphere.  Some  have  the  tooth  as  distinct 
as  in  Monodonta  ;  but  they  may  at  once  be  known  by 
having  no  umbilicus,  even  although  the  inner  lip  may 
have  a  slight  marginal  groove.  But  here,  as  nature  has 
reached  the  highest  point  of  developement,  she  again  re- 
cedes ;  the  spire  gradually  lengthens,  the  tooth  becomes 
a  simple  angle,  and  we  enter  on  the  smooth  division  of 
the  group,  forming  our  sub-genus  CaUiofitoma.  The 
Trochus  zizyphinus  of  British  writers  will  give  a  very 
good  idea  of  these  shells  ,•  they  are  nearly  all  either  per- 
fectly smooth  or  slightly  granulated,  of  a  light  and  ele- 
gant form,  a  long  and  pointed  spire,  and  no  umbilicus : 


CHAP.  VII.       MONODONTA.  THE    SUB-GENERA.  219 

several  species,  but  little  known  *,  are  found  in  the  Medi- 
terranean ;  and  these  are  the  most  trochiform, — that  is, 
the  basal  whorl  is  unusually  flattened,  which  renders  the 
aperture  narrow :  those  from  the  Pacific,  on  the  contrary, 
are  more  ventricose,  —  thus  representing  Cidaris  and  the 
SenectincB.     This  modification  of  form  is  to  constitute 
the  passage  which  here  takes  place  between  the  five  types 
of  Trochus  and  those  of  Monodonta.  The  last  sub-genus, 
Pagodella,  is  the  only  one  containing  shells  that  are  not 
perlaceous.     The  student,  at  first  sight,  would  think  this 
was  a  most  heterogenous  group,  for  it  contains  species  of 
very  different  forms:   some  are  so  like  European  Callio- 
stonice,  that  they  might  be  strictly  arranged  as  such,  if 
the  substance  (tf  their  shell  was  not  regarded ;  others 
are  equally  conic,  but  instead  of  being  smooth,  are  beset 
with  nodulous  granules ;  while  others,  again,  are  formed 
precisely  the  same  as  our  first  type,  Chlorostoma,  but  yet 
have  no  umbilicus.      But  this  is  at  once  explained  by 
the  situation  of  Pagodella,  which  is  intermediate  between 
CalUostoma  and  Chlorostoma.     So  exquisitely,  also,  has 
nature  blended  this  genus  with  the  last-named  group, 
that  there  is  one  species,  the   Trochus  Merula  of  La- 
marck, w^hich  unites  in  itself  still  more  closely  the  cha- 
racters of  Chlorostoma  and  Pagodella  ;  it  has  the  shape, 
colour,  and  pearly  substance  of  the  first,  and  the  flat- 
tened imperforate  lip  of  the  last ;  it  may,  in  fact,  be 
called  either  a  perlaceous  Pagodella  or  an  imperforate 
Chlorostoma.      Having    now    gone    through  the    genus 
Trochus,  we  proceed  to  the  next,  or  sub-typical  group. 
(205.)  On  entering  the  genus  Monodonta,  we  must 
refer  to  what  has  been  just  said  on  the  Oceanic  f  spe- 
cies of  CalUostoma,  the  greater  convexity  of  whose  basal 
whorl  cannot  fail  to  have  been  remarked ;  thus  we  are  con- 
ducted to  Elenchus,  the  first  sub-genus   of  the  present 
group,  and  found  only  in  the  same  latitudes.     These 

*  It  is  of  these,  we  believe,  that  the  genus  Margarita  has  been  pro- 
posed, to  include  such  as  have  "  the  operculum  of  few  whorls." 

t  The  Continental  naturalists  employ  this  term  to  designate  the  pro- 
ductions of  those  countries  or  seas  lying  in  the  Great  Pacific  Ocean. 


220 


SHELLS    AND    SHELL-FISH. 


PART  I. 


splendid  shells,  although  mostly  of  a  small  size,  have  a 
brilliancy  in  the  emerald  green  of  their  apertures,  which  is 
perfectly  unrivalled  in  this  family  (^^.40.)  like  the  Callio- 
6-tomcB,  the  basal  whorl  is  convex, — more  so,  indeed,  than 
40  ^-««a^*p''?r^     ..^..^       ill  any  other  of  this  ge- 

nus, except  that  to  which 
it  leads  ;  the  spire  is  also 
generally  more  produced, 
and  in  one  species  (a)  is 
so  long  that  it  resembles 
a  small  Turritella.  It  is  among  these  shells  that  the 
most  prevalent  character  of  Monodonta  appears.  The 
base  of  the  pillar  in  some  forms  an  angle,  and  in  others 
a  small  but  very  distinct  tooth  :  their  exterior  is  always 
smooth.*  Next  to  these  we  place  a  small  group  of 
equally  ventricose  shells,  to  which  we  retain  Lamarck's 
name  oi  Monodonta ;  they  have,  in  fact,  almost  the  form 
of  Senecti,  but  they  are  small,  and  the  pillar  is  both 
umbilicated  and  toothed  :  in  some,  these  characters  are 
very  slightly  developed ;  in  others,  they  are  very  strong  ; 
and  this  variation  takes  place  in  species  otherwise 
so  much  alike,  that  they  might  almost  be  taken  for 
the  same  at  different  periods  of  growth.  They  are 
mostly  finely  granulated,  and  sometimes  striated  within  ; 
but  their  ventricose  aspect  is  altogether  peculiar ;  the 
umbilicus  is  always  smooth  round  its  edges,  but  varies 
in  its  size.  In  the  next  sub-genus,  Fragella,  the 
basal  tooth  is  so  large,  that  its  projection,  joined  with 
the  teeth  on  the  inner  margin  of  the  outer  lip,  gives  the 
aperture  an  appearance  of  being  distorted.  The  well- 
known  little  shell  called  the  strawberry  trochus,  is  the 
type ;  and,  by  its  depressed  form,  pointed  spire,  and 
large  umbilicus,  reminds  us  immediately  of  a  genuine 
Trochus :  the  surface  of  nearly  all  is  beautifully  granu- 
lated. In  our  fourth  group,  or  Monilea,  the  umbilicus 
and  its  singular  marginal  rim  are  precisely  the  same  as 
in  Chloroatoma,  except  that  the  umbilicus  is  wider,  the 


*  This  beautiful  group  was  well  known  to  Humphrey,  whose  name,  im- 
posed near  forty  years  ago,  we  have  of  course  retained,  instead  of  bome 
others  recently  given  by  the  French  nomenclators. 


CHAP.  VII.  SOLARIUM. ONUSTUS.  221 

shape  more  depressed  and  trochiform,  and  the  surface  of 
the  shell  often  granulated  ;  the  only  remnant  of  the  tooth 
is  shown  by  one  or  two  small  tubercles  or  notches  at  the 
base  of  the  outer  lip.  Several  species^  mostly  of  a  small 
size,  are  now  before  us,  all  of  which  are  natives  of  warm 
climates  or  of  the  Pacific  Ocean.  Lastly,  we  find  in 
this  genus,  as  well  as  in  Trochus,  one  division  which 
have  not  perlaceous  shells,  but  which,  possesses  a 
well-defined  tooth.  These  species  we  include  under  the 
name  of  Echinella.  The  most  typical  is  that  figured 
in  the  Ency.  Meth.  (pi.  417-  fig.  6.)  as  Monodonta  coro- 
naria, — a  shell  which  is  a  perfect  prototype  of  our  Pa- 
godella  echinata  :  the  species  yet  known  are  few;  but  of 
these  we  possess  the  connecting  link  to  Elenclms,  in  our 
E.  gramdata.  We  are  thus  brought  back  to  Elenchus, 
where  we  commenced  our  survey  of  Monodonta.  The 
naturalist  will  not  fail  to  perceive,  that  in  thus  resting 
our  arrangement  upon  affinity,  we  have  indicated  strong 
relations  of  analogy  between  Trochus  and  Mono- 
donta :  to  these  we  shall  presently  return. 

(206.)  The  two  remaining  genera.  Solarium  and 
Onustus,  do  not  comprise  more  than  a  few  recent  species, 
although  it  is  highly  probable  that  many  of  the  imper- 
fectly preserved  fossil  discoid  shells  belong  to  the  first, 
and  some  few  also  appertain  to  the  last.  On  receding 
from  the  typical  species  of  Solarium,  the  spire  becomes 
more  prominent,  and  the  edge  of  the  body- whorl  dilated 
to  form  a  sharp  edge,  so  thin  as  easily  to  be  broken  off ; 
the  crenated  margin  of  the  umbilicus  of  these  shells,  how- 
ever, indicates  their  affinity  to  the  singular  genus  Onustus. 
From  certain  slight  and  irregular  indentations  on  the 
preliminary  whorls  of  the  spire,  we  suspect  that,  at  an 
early  age,  many  of  these  animals  gather  small  fragments, 
and  fasten  them  upon  their  shells  ;  but  that,  when  older, 
these  extraneous  substances  either  fall  off,  or  are  volun- 
tarily discharged;  just  as  if  the  animal,  having  acquired 
its  full  powers  by  age,  was  able  to  fabricate  its  own  ha- 
bitation without  calling  in  other  assistance.  Now,  the 
same  advance  which  we  have  thus  stated  as  taking  place 


222  SHELLS    AND    SHELL-FISH.  PART  I. 

from  Solarium  to  Onustus  on  one  side,  can  also  be  dis- 
covered on  the  other  side  from  Canthorbis.  The  gra- 
dation, in  fact,  is  equally  perfect  on  both  sides :  the 
two  extremities  of  the  column  of  the  Trochin^,  com- 
mencing with  the  sub-umbilicated  species  of  Canthoi'his, 
and  ending  with  the  sharp-edged  Onustus,  meet  to- 
gether in  the  Onustus  agglutinans*,  which  thus  closes 
the  circle  of  the  five  genera  of  the  TRocHiNiE. 

(207.)  The  two  aberrant  types  of  this  family  are  as 
remarkable  for  the  paucity  of  their  forms,  as  the  typi- 
cal Trochin^e  are  otherwise.  Of  the  RotelUnce,  in  fact, 
we  can  only  enumerate  two  genera  ;  and  one  of  these  not 
so  effectually  as  we  could  wish.  We  think  the  Turbo  Ni- 
cobaricus  is  the  type  of  a  sub-genus  (^Chrysostoma  Sw.) 
much  more  related  by  its  shell  to  Rotella  than  to 
Senectus,  even  if  its  operculum  should  prove  to  be 
shelly.  It  differs  from  all  other  Trochidcs,  in  having 
a  very  thick  deposition  of  shelly  matter  spreading  over 
the  umbilicus,  which  it  almost  conceals :  it  does  not, 
however,  extend  near  so  far  as  in  Rotella;  and  yet  both 
shells  are  evidently  highly  polished  by  their  animals. 
On  this  account,  therefore,  and  in  the  absence  of  all 
knowledge  of  the  animal,  we  place  it  as  the  represent- 
ative, among  the  RotelUnce,  of  Senectus  and  Monodonta. 
Of  the  fossil  genus  Pleurotomaria  very  little  can  be 
said  :  it  obviously  enters  into  our  present  family,  from 
the  trochiform  shape  of  its  shell ;  and  the  foregoing 
analysis  renders  its  station  in  any  other  group  highly 
improbable  ;  we  place  it,  therefore,  between  Rotella 
and  Phasianella,  as  the  type  of  a  sub-family,  the  other 
members  of  which  cannot  now  be  distinctly  ascertained. 
The  truth  is,  that  in  this  and  numerous  other  instances, 
the  study  of  fossil  conchology  is  impeded  by  insur- 
mountable difficulties,  which  must  always  exist.  How 
many  genera  are  in  our  systems,  belonging  to  the  older 

*  It  is  somewhat  remarkable,  that,  from  Lamarck's  description  of  this 
shell,  it  would  seem  to  have  the  umbilicus  open  when  young,  but  closed 
when  it  has  reached  maturity.  In  two  fine  specimens  now  on  the  table,  it 
is  completely  covered  ;  and  yet  there  is  a  fossil  species  from  Hordwell, 
where  it  is  perfectly  open,  although  not  large. 


CHAP.   VII.    TROCHID.E. TURBID^. 


ANALOGIES. 


223 


geological  beds,  which  we  only  know  from  casts  and 
mutilated  fragments  !  and  how  many  others,  even  in 
the  newer  formations,  which  it  is  impossible  to  arrange 
with  precision,  from  ignorance  of  the  animal !  These  are 
the  true  reasons  which  lead  us  to  say  as  little  as  pos- 
sible upon  all  those  fossil  genera  whose  affinities  are 
doubtful ;  since,  from  the  peculiar  nature  of  the  object 
we  have  in  view,  we  would  rather  incur  the  imputation 
of  overstrained  caution,  than  the  opposite  extreme. 

(208.)  We  have  hitherto  considered  only  the  affini- 
ties of  the  TrochidcB  ;  let  us  now  turn  to  their  analogies. 
Our  first  table  will  be  of  the  primary  divisions,  or  sub- 
families, which  represent  those  of  the  Turh'idcR  in  the 
following  manner  :  — 

Analogies  of  the  Sub-families  of  the  Trochid^  and  the 

Turbid^. 


Sub-families  of 

TrockidiZ. 
Typical  Genera. 

Senectus. 


Trochus. 

ROTELLA. 

Pleurotomaria. 
Phasianella. 


Analogical  Characters. 


c  (1.  Sub-typical.) 

•J  Shell  globose  ;  operculum  shelly 
c     spire  short,  obtuse,  ventricose 
(2.  Typical.) 
Spire  pointed;  whorls  more  nu- 
merous ;  operculum  horny. 
(3.  Aberrant.) 
Shell  depressed  ;  inner  lip  thick 
ened. 

C  Trochiform  ;  the  outer  lip  with  a 
X      marginal  slit  or  sinus. 

f  Spire  greatly  lengthened 
X     culum  shelly. 


Sub-families  of  the 

Turbidai. 

Typical  Genera. 

Ampillaria. 


\ 


\ 


Melania.    3 


Thallicera. 


Ianthina. 


^   ^'  i       TURRITELLA. 


Whatever  may  be  the  rank  of  Pleurotomaria,  it  is 
certainly  the  prototype  of  Ianthina.  These  latter  shells 
are  so  excessively  brittle,  that  not  one  in  five  hundred 
are  perfect  j  but  the  sinus,  although  neither  so  long  nor 
so  narrow  as  in  Pleurotomaria,  is  nevertheless  fully  de- 
veloped in  the  perfect  shells,  but  more  especially  in  our 
/.  gJohosa.*  The  long-spined  Turritellce  represent 
Phasianella,  and  both  have  a  shelly  operculum.  The 
other  analogies  are  not  so  striking,—  excepting,  perhaps. 


•  Zool.  111.  1st  Series. 


224 


SHELLS    AND    SHELL-FISH. 


PART  I. 


that  of  Senectus  to  Ampullaria;  both  being  large  globose 
shells,  and  the  latter  sometimes  closed  with  a  shelly 
operculum.  The  curious  reader,  who  may  be  desirous 
of  prosecuting  these  analogies  further,  may  compare 
them,  at  his  leisure,  with  many  others  in  the  volume. 

(209.)  We  shall   now  bring  together  the   genera  of 
the  two  sub-families. 

Analogies  of  the  Senectin^  and  the  Trochin^. 


Genera  of  the 
Senectin^. 

Senectus. 

Marmarostoma. 

Delphinula. 
Cyclocantha  ? 

CiDARIS. 


Analogical  Characters. 

CTypiral  of  their  respective  circles;  7 
\     volutions  convex.  j 

f  Sub-typical ;  umbilicus  with  a  ba-  7 
\     sal  groove.  5 

f  Nearly  discoid;    umbilicus  very 7 
X     deep ;  pillar  none.  3 

Shell  not  perlaceous  ;  trochiform. 
f  Aperture    oblique  ;      operculum  7 
I     shelly.  3 


Genera  of  the 
Trochi\.«. 

Trochus. 

monodonta. 

scalaria. 
Onustus. 
Canthorbis. 


Our  only  doubt  relates  to  what  is  the  true  type 
between  Delphinula  and  Cidat-is.  It  is  either  the  shells 
we  have  before  mentioned,  or  those  of  which  Turbo 
pagodus  is  the  type,  where  the  operculum  is  horny. 
We  may  now  turn  to  the 


Analogies  of  the  Sub-genera  0/ Canthorbis. 


Sub-genera  of 
Canthorbis. 

Tuhicanthus. 

Canthorbis. 
Pyramidea. 
Lamprostoma. 

Carinidea. 


Analogical  Characters. 

C  Apertu  re  obliquely  round  or  oval ;  7 
I     smooth.  5 

f  Greatly  depressed  ;  the  sides  ca-  7 
(_     rinated  ;  umbilicus  small.  j 

Aperture  thin,  sharp,  brittle. 

("Aperture  strongly  toothed  or  tu- 7 
X  berrulated  ;  striated  within.  3 
("Aperture  nearly  entire,  slightly") 
X     angulated  ;  smooth  within.         3 


Genera  of  the 
Trochinje. 

Canthorbis. 

Onustus. 

solartum. 

Monodonta. 

Trochus. 


The  re^'.ults  of  this  table  will  explain  why  we  have 
thought  it  expedient  to  characterise  as  sub-genera  the 
types  of  such  a  small  group  as  Canthorbis ;  for  the  shells 
it  contains  are  so  remarkably  varied,  that,  without  some 


CHAP.    VII.  TROCHID^.  —  CANTHORBTS.  225 

clue  to  the  meaning  of  this  variation^  it  might  appear  a 
questionable  group.  The  only  one  of  these  analogies 
on  which  we  have  any  doubts^  is  that  between  Carini- 
dea  and  Trochus :  we  are,  in  fact,  at  a  loss  to  know 
whether  Trochus  Niloticus  and  Turho  Pica  are  the  real 
types  of  Carinidea,  in  which  case  they  would  open  a 
passage  from  the  large  Canthorbi  to  the  small  and 
moderate-sized  shells  of  our  genus  Trochus:  the  strong 
and  unquestionable  affinity,  however,  of  Carinidea  con- 
cavus*  to  our  sub-genus  Chlorostornus,  although  the 
one  is  a  large  and  the  other  a  small  shell,  cannot  be 
disturbed.  But,  on  the  other  hand,  even  if  the  passage 
from  Canthorhis  to  Trochus  is  made  by  Niloticus  and 
Pica,  the  difference  is  one  of  very  inferior  moment. 
Two  things  are  certain  :  one,  that  Canthorhis  is  the 
intermediate  group,  which  connects  the  TrochincB  to 
the  SenectincB ;  the  other,  that  it  equally  connects  our 
genera  Trochus  dinA  Onustus:  for  every  conchologist  will 
perceive  that  Tubicanthus  runs  into  Cidaris  by  means 
of  C.  rugosus  and  Cookii.  There  is,  however,  another 
analogy  belonging  to  Canthorhis,  too  remarkable  to  be 
passed  over  :  it  is,  in  its  own  group,  what  Cerithium 
is  in  the  circle  of  the  StrombidcB:  this  is  shown  in  its 
twisted  and  outwardly-curved  pillar,  as  well  as  the 
numerous  volutions,  and  the  consequent  length  of  the 
spire.  According  to  this  view,  Pyramidea  and  Lam- 
prostoma  would  be  the  types, — since  they  are  the  most 
conical  and  elevated  of  all  the  others. 

(210.)  We  now  come  to  the  sub-genera  of  the  two 
typical  groups,  Trochus  and  Monodonta.  It  has  been 
seen  that  each  forms  a  circular  group  ;  and  the  pre- 
ceding observations  will,  in  some  measure,  have  pre- 
pared the  reader  for  the  following  general  exposition 
of  their  sub-genera.  The  genus  Margarita  of  Leach 
appears  to  us  a  purely  artificial  group,  partly  composed 
of  our  umbilicated  Trochi,  and  of  the  true  Calliostomce  ; 
we  have  therefore  not  adopted  it. 

*  Our  specimen,  fortunately,  possesses  its  operculum,  and  has  never  been 
cleaned. 


226 


SHELLS    AND    SHELL- FISH. 


PART  I. 


Analogies  of  the  Sub-genera  oyTRocHus  and  Monodonta. 


Sub-gencra  of 
Trochus. 

Trochus. 
TrochUicm. 

Calliostoma. 


Pagodella. 


Chlorostoma. 


] 


Analogical  Characters. 

More  or  less  umbilicated,  but  the 
umbilicus  always  smooth. 

Base  of  tlie  pillar  forming  a  pro-  1 
minent  tootii.  J 

Imperforate,  smooth,  or  slightly  "J 
granulated  ;  basal  whorl  some-  { 
times  ventricose  ;  spire  long,  f 
pointed.  j 

Shell  not  perlaceous,  pyramidical. 

Deeply  umbilicated;  the  inner ^ 
lip  thickened  and  truncate  > 
half  way  round  the  margin,        j 


Sub-genera  of 

Mo.NODOiV. 

Monodonta. 
Fragella. 

Elenchus. 

Echinella. 
Monilea. 


These  analogical  resemblances  are  so  close,  that,  but 
for  the  former  explanations,  an  incautious  conchologist 
might  easily  mistake  one  for  the  other.  Unfortunately, 
we  are  in  total  ignorance  of  the  animals  of  all  these, 
Trochus  excepted.  Whether  they  have  each  a  peculiar 
modification  of  form,  or  whether  Nature  has  confined 
herself  to  tracing  out  these  variations  by  the  shells 
alone,  are  questions  which  time  alone  will  develope. 

(211.)  "A  natural  arrangement,"  as  an  eminent  en- 
tomologist has  more  than  once  observed,  "^  will  stand  any 
test."  We  have  now  placed  it  in  the  reader's  power  to 
act  upon  this  hint,  by  applying  all  those  "  tests  "  which 
our  preceding  diagrams  have  supplied,  to  our  arrange- 
ment of  this  family.  There  is  one,  however,  which, 
from  its  singularity,  may  here  be  mentioned. 


Analogies  of  the  Tbochid^  to  the  AcHAxiNiE, 


Sub- families  of 

TllOCllIU/E. 

Senectin-e. 

Trochin*. 

kotellin.e. 

Pleurotomin^. 

FilASIANELLIN£. 


Analogical  Characters. 

("Ventricose  ;  sjiire  short ;  aperture  \ 
X     always  entire.  J 

C  Spire  conic,  inore  developed  ;  base  \ 
X     of  the  pillar  notched  or  toothed.  3 
Nearly  discoid. 

r  Outer  lip,  either  above  or  below,7 
X      with  a  slit.  j 

Spire  very  much  produced. 


Genera  of  the 

ACH.\T1N^. 

Bllimls. 

achatina. 

Cyclostoma. 

Helicina. 

CLAL'SILIA. 


CHAP.   VII.  TROCHIDiE. ACHATIX^.  227 

These  analogies,  of  course,  are  much  more  rem.ote 
than  those  we  have  been  tracing,  because  the  groups 
themselves  are  much  more  remote;  and  yet  the  same  mode 
of  variation  is  preserved  in  two  different  families — one 
marine,  the  other  terrestrial.  The  RotellcB  in  one,  and 
the  Cyclostomcd  in  the  other,  are  the  most  discoid  shells 
in  their  respective  families  ;  while,  at  the  opposite  side 
of  the  circle,  we  find  the  long-spired  Phasianellce  repre- 
senting the  still  longer-spired  ClausilicB.  Some  of  the 
Helicince  have  a  deep  narrow  slit  at  the  base  of  their  aper- 
ture, precisely  similar  to  that  on  the  outer  lip  in  Pleu- 
rotomaria  ;  and  in  both  instances  this  structure  is  only  a 
repetition  of  what  is  seen  in  lanthina,  Scissurella,  and 
Pleurotoma.  The  two  first  analogies  equally  hold  good, 
so  that  the  two  groups  mutually  test  each  other. 

(212.)  We  have  placed  the  Trochidce  next  to  the 
Helicidcp,  under  the  belief  that  they  followed  each  other, 
although  the  links  of  connection  were  wanting.  It  is 
clear,  that  of  all  the  types  of  the  Trochidce,  Rotella  is 
that  which  by  its  general  form  makes  the  nearest  ap- 
proach to  Helix  ;  while  the  thickening  of  the  inner  lip, 
which  spreads  over  the  umbilicus,  is  found  also,  but  in 
a  less  degree,  in  many  of  the  land  volutes,  Lucernince. 
But  a  singular  discovery,  recently  made,  has  thrown  an 
entirely  new  light  upon  this  interesting  question.  Among 
a  considerable  number  of  freshwater  Planorbi,  all  of  one 
species,  which  were  sent  us  from  Brazil,  we  picked  out 
two  helix-looking  shells,  so  precisely  of  the  same  oiiva 
brown  colour,  and  of  the  same  size,  as  the  others,  that 
none  but  a  conchologist  would  have  been  led  to  examine 
them.  They  appeared,  in  fact,  like  two  little  land-snails 
of  the  sub-genus  Zonites,  that  had  fallen  into  the  water 
where  the  Planorhi  had  been  found,  —  their  outside  being 
discoloured,  and  covered  with  little  particles  of  dirt  and 
sand.  On  placing  them,  however,  under  the  magnifier, 
a  conchologist  can  alone  judge  of  our  astonishment  at 
finding  that  the  whole  of  the  shell  was  actually  com- 
posed of  little  stones  and  grains  of  sand  only,  agglutinated 
together,  yet  with  so  much  skill,  by  the  animal,  that  the 

Q  2 


228  SHELLS    AND    SHELL-FISH.  PART  I. 

regular  turns  of  the  volutions  of  the  spire^  and  the  form 
of  the  umbilicus,  was  most  accurately  preserved  :  they 
were,  in  short,  freshwater  carriers  —  absolute  counter- 
parts of  their  marine  brethren,  Onustus.  As  we  can 
find  no  notice,  or  even  allusion,  to  such  an  extraordinary 
genus  of  shells  in  any  writer,  we  have  considered  it  new, 
and  affixed  to  it  the  name  of  Thelidomus.  In  regard  to 
its  affinity,  we  suspect  that  it  fills  the  same  situation 
among  the  Rotellince  which  Onustus  does  among  the 
Trochintp  :  this  will  make  it  the  most  aberrant  type,  and 
consequently  that  which  comes  nearest  to  the  HelicidfB, 
whose  form  it  actually  possesses.  The  annexed  figures 
{fig.  41.)  are  taken  from  the  only  two 
specimens  in  our  cabinet  which  we  have 
either  seen  or  heard  of ;  the  line  denotes 
their  natural  size.  Thus,  there  is  ground 
for  supposing  that  the  passage  from  the 
marine  TrochidcB  to  the  terrestrial  snails 
is  marked  by  one  or  more  fluviatile  types, 
just  as  is  the  passage  on  the  other  side  of 
the  Helicidcp,  marked  by  the  Limnacince.  The  accidental 
discovery,  also,  of  this  extraordinary  shell,  will  probably 
induce  naturalists  to  a  more  accurate  examination  of  the 
fossil  turbinated  univalves  than  they  have  received  ,•  for 
it  is  clear,  that,  although  Thelidomus  opens  the  path  to 
the  Helicidce,  there  must  be  several  other  forms  between 
the  two,  either  extinct  or  undiscovered. 


CHAP.  VIII. 


THE  PHYTOPHAGOUS  GASTROPODS  CONCLUDED. THE   HALIOTIDj«, 

OR    EAR-SHELLS,    AND    THE    NA71CID^,    OR    NERITS. 

(213.)  The  Haliotid.^,  or  ear-shells,  follow  the 
TrochidfE,  and,  like  them,  in  their  typical  examples,  are 
of  a  rich  pearly  and  iridescent  substance.     They  have 


CHAP.  VIII.  haliotida:  generally.  229 

been  confounded,  even  by  Cuvier,  with  the  true  Scuti- 
branchia,  merely  because,  like  them  and  the  Tuhuli- 
branchia,  their  mode  of  generation  is  the  same.  If  this 
latter  consideration  is  of  such  importance,  all  these  three 
should  form  one  group ;  and  not  only  so,  but  they  should 
be  united  to  the  Dythera,  or  bivalves, —  since  they  also  are 
fecundated  in  a  similar  manner.  The  fact,  however, 
appears  to  come  out,  by  analysis,  that  the  Haliotidcs  are 
the  representatives  of  the  limpets  (^Scutihranchia)  in  the 
great  circle  of  the  phytophagous  gastropods,  just  as  the 
naked  dorises  (N'lidibranchia)  represent  the  limpets 
(^Scutihrancliia)  in  the  entire  class  of  shell-fish  (^Testa- 
cea).  And  thus,  no  less  a  naturalist  than  Cuvier,  from 
not  attending  to  the  two  sorts  of  relationships,  —  analogy 
and  affinity,  —  has  mistaken  the  one  for  the  other  in  both 
instances,  and  obscured  one  of  the  most  beautiful  tran- 
sitions in  nature.  To  this  most  accurate  anatomist, 
however,  we  are  indebted  for  the  first  knowledge  of  the 
animal  of  Haliotis,  and  to  M.  Quoy  for  that  of  Stomatia.* 
Without  entering  into  the  details,  we  may  simply  state 
that  the  structure  of  the  first  evinces  an  analogy  to  that 
of  the  Patellida,  or  limpets;  while  the  animal  of  Stoma- 
tia  still  more  closely  resembles  that  of  the  Trochidce, 
and  more  especially  of  Phasianella  and  Cidaris.  The 
determination  of  these  two  facts  are  of  the  highest  im- 
portance, since  it  enables  us  to  discern  the  two  typical 
groups  ;  while  a  beautiful  delineation  of  the  ^S".  Chinensis, 
among  the  unpublished  drawings  of  Guilding,  and  of  the 
animal  of  a  Sigaretus  by  M.  Quoy,  makes  us  actually 
acquainted  with  the  inhabitants  of  four  out  of  the  five 
genera  which  compose  the  family. 

(214.)  In  regard  to  the  shells  of  the  Haliotidcs,  they 
are  easily  and  certainly  recognised  :  they  may  be  called, 
indeed,  turbinated  or  spiral  limpets,  inasmuch  as  nearly 
the  whole  have  some  slight  developement  of  a  spire  ; 
but  an  indication  of  the  pillar  is  only  seen  in  that  genus 
which  comes  nearest  to  the  Ti'ochidcs, — namely,  Calyp- 

*  Stomatella  tacheMe,  Vov.  d' Astrolabe,  pi.  Qo.  bis. 
Q    3 


I 


230  SHELLS    AND    SHELL-FISH.  PART  I. 

trcea*  The  whole  may,  therefore,  be  characterised  as 
patelliform  shells,  always  possessing  either  a  small  spire 
of  two  or  more  volutions,  or  some  internal  support  within, 
although  the  pillar  is  wanting.  They  are,  in  fact,  the  dis- 
coid type  of  the  phytophagous  Gasteropoda;  representing 
on  one  side  the  testaceous  Cephalopoda,  and  on  the  other 
the  Scutibranchia,  or  limpets.  Like  the  Volutidcp,  they 
have  no  operculum,  and  both  represent  each  other  in 
the  extreme  shortness  of  their  spire.  In  comparison 
to  those  we  have  already  noticed,  this  is  a  very  small 
family, — so  small,  indeed,  that  its  primary  divisions 
are  only  of  the  rank  of  genera.  They  are,  in  a  manner, 
fixed  or  sedentary  shell-fish ;  for,  although  some  are 
capable  of  locomotion,  they  must  move  but  very  little, 
since  the  obvious  construction  of  their  shells  t  is  mani- 
festly for  the  purpose  of  adhesion.  Hence  they  are 
found  closely  affixed  to  rocks  or  other  substances  near 
or  within  the  sea.  The  round  holes  in  the  perforated 
ear-shells  (many  species  of  which  are  of  a  large  size  and 
splendidly  iridescent)  are  for  the  passage  of  slender 
filaments  which  the  animal  can  protrude  at  pleasure : 
these,  of  course,  do  not  exist  in  those  ear-shells  which 
are  without  perforations ;  but  in  both  the  mantle  of  the 
animal  is  highly  ornamented, —  being  in  Stomatia  regu- 
larly cut  into  numerous  points,  like  the  teeth  of  a  saw  ; 
and  these,  in  Haliotis,  assume  the  more  lengthened  shape 
of  filaments.  Both  these,  which  constitute  the  two 
typical  genera,  enjoy  the  free  power  of  locomotion,  for 
we  do  not  observe  that  the  contour  of  the  shell  of  in- 
dividuals of  the  same  species  ever  varies, — a  clear  proof 
that  they  never  take  the  form  of  that  substance  they 
may  happen  to  be  attached  to.  In  Calyptreea  and  Cre- 
piduln,  however,  the  case  is  different.  We  have  no 
doubt  that  the  greater  part,  at  least,  of  these  shell-fish 

*  Cuvier,  indeed,  admits  these  and  similar  patelliform  shells  approxi- 
mate in  their  animals  to  the  Trochidie,  and  yet  he  places  them  widely 
apart  from  Stojuatia,  whose  structure  in  its  soft  parts  is  still  more  like 
that  of  Trochus. 

t  Except,  of  course,  Sigaretus,  which  has  its  shell  enveloped  on  its 
back,  as  representing  the  Tectibranchia. 


CHAP.   VIII.  STOMATIA_,   THE  TYPES.  231 

live  and  die  on  the  very  spot  where  they  were  originally 
born  ;  for  the  circumference  of  almost  every  individual 
presents  a  different  contour,  according  to  the  surface  of 
the  substance  on  which  it  adhered.  Like  the  TrocMdcp, 
we  find  that  the  two  typical  divisions  alone  are  per- 
laceous.  One  species  of  Haliotis  is  found  on  our 
south-western  coasts ;  but  the  greater  part  of  these 
splendid  shells,  as  well  as  Stomatia,  come  from  warm 
latitudes. 

(215.)  The  five  primary  divisions  of  the  family  are 
only  genera,  —  Haliotis  and  Stomatia  being  the  most 
typical  j  then  follow  Calyptrcea,  Sigaretus,  and  Cre- 
pidula.  The  whole  of  these  constitute  a  circular  group, 
connected  by  the  third  type  to  the  Trochidce,  and  by 
the  fifth  to  the  NeritidcE  by  means  of  Navicella.  The 
scientific  reader  will  find  all  these  groups  sufficiently 
characterised  in  our  arrangement;  but  a  few  general 
remarks  appear  called  for  in  this  place.  It  is  singular 
that,  if  any  modification  in  the  structure  of  the  animals 
in  Haliotis  exist,  they  are  not  conspicuously*  shown  in 
these  shells,  with  the  exception  of  one,  the  Haliotis 
asinma,  or  ass's  ear ;  while  in  Stomatia  (of  which 
Quoy  has  figured  the  animal  of  the  typical  species),  the 
variations  in  the  shell  are  so  many,  that  there  can  be 
little  doubt  of  their  being  accompanied  by  a  corre- 
sponding variation  in  their  animals.  As  we  are  some- 
what undecided  whether  these  should  all  receive  sub- 
generic  names  (as  in  the  instance  of  Stomatella),  we 
shall  here  only  mention  what  appear  to  be  the  five 
types,  t  >S'.  planulata  obviously  unites  Stomatella  to 
Haliotis,  by  means  of  its  prototype  H.  asinina.  In  both, 
the  spire  is  very  short,  the  form  oblong,  and  the  outer 
surface  smooth.  S,  auricula  seems  to  be  the  next  type, 
where  the  spire  is  sufficiently  developed  to  be  elevated 
above  the  surface  of  the  body-whorl ;   then  comes  the 

*  Perhaps,  however,  conchologists  have  paid  too  little  attention  to  the 
Haliotis  in  the  variations  of  their  form. 

t  It  is  curious  that  Mr.  Sowerby,  unaware  of  our  views,  should  have  hit 
upon  all  these,  and  urged  this  variation  as  :\  reason  for  not  adopting 
Lamarck's  Stomatella  :  see  his  Genera  of  Sheds. 

a  4 


232 


SHELLS    AND    SHELL-FISH. 


PART  I. 


typical  form  in  Stotnatia  imbricata  and  sulcifera,  which 
appear  to  have  from  two  to  three  distinct  spiral  whorls*, 
but  Still  without  any  ridges  or  angles,  although  the 
outer  surface  is  finely  imbricated.  In  duplicata  the 
spire  is  still  more  developed,  angulated,  and  marked 
with  granulated  tubercles ;  so  that,  in  fact,  it  much 
more  resembles  one  of  the  SenectincB,  and  particularly 
Cidaris,  than  a  Stomatia,  while  its  angulated  shape  and 
tubercles  remind  us  of  Delphinula.  Lastly,  we  have  a 
form,  in  ^S".  phimotis,  very  distinct  from  all  these :  the 
spire  is  again  shorter,  more  like  that  of  planvlata  and 
auricula,  but  it  is  irregularly  formed ;  the  outside  of  the 
shell  is  rough  and  angulated,  as  in  duplicata,  so  that  it 
unites  the  form  of  all  these  three  ;  we  have  an  indis- 
tinct recollection,  also,  that  the  substance  of  this  shell  is 
not  perlaceous,  like  all  the  preceding  species.  Now,  the 
reader,  if  he  turns  to  our  distribution  of  the  Trochidce, 
and  of  the  types  therein  contained,  cannot  fail  to  be 
struck  with  the  singidar  coincidence  of  these  five  spe- 
cies agreeing  with  the  variations  there  pointed  out. 
This  will  be  seen  more  clearly  by  throwing  them  into 
a  tabular  form. 

Analogies  of  the  Types  of  Stomatia. 


Types  of 
Stomatia. 

S.  planulata. 

phimotis,  or 
obscurata  Lam. 

duplicata. 

Auricula. 

imbricata. 


Analogies. 

\  Spire  flattened ;  outer  surface  7 
)      smooth.  3 

rShell  and  spire  irregular;  sub-T 
■<  stance  not  perlaceous  ;  outer  > 
C     surface  rough,  carinated.  J 

f  Spire  elevated  ;  the  whorls  angu-  7 
I     lated  and  coronated.  J 

f  Spire  short,  raised  above  the  body- 7         c^„^^/,„ 
\     whorl ;  perlaceous.  j         ^enectus. 


I 


Spire  more  elevated  and  developed,  ^ 
but  without  any  angles  or  tu-  > 
bercles.  J 


TROCHID.E. 

Types. 

Jiutella, 
Cidaris. 

Onustits. 

Delphinula, 
Canthorbis. 


Trochus. 


We  are  unacquainted  with  any  of  the  fossil  species, 
but  we  have  no  doubt,  after  this  exposition,   that  they 


*  Sowerby's  Genera,  art.  Stomatia,  figs.  1  and  2. 


CHAP.   VIII.  CALYPTR^A.  233 

will  arrange  themselves  under  one  or  other  of  these 
types.  Without  enlarging  further  upon  these  analogies, 
we  may  briefly  state  that  they  are  in  perfect  uniformity 
with  that  principle  of  variation  which  runs  through 
the  whole  of  the  animal  kingdom.  It  was  long  ago 
announced  by  one  of  the  most  philosophic  naturalists 
of  the  age,  that  when  Nature^  so  to  speak,  is  about 
entering  a  large  assemblage,  she  gives,  as  it  were,  in 
the  onset,  a  sketch  of  the  five  leading  forms  she 
intends  to  adhere  to,  although  under  innumerable  mo- 
difications. Thus,  in  the  class  of  Acrita,  as  MacLeay 
observes,  she  typifies  the  five  great  classes  of  animals  ; 
and  thus  again,  in  the  very  first  group  of  the  spiral 
univalves,  she  presents  us  with  indications  of  the  five 
great  families  of  the  phytophagous  and  zoophagous 
Gasteropoda,  all  concentrated  in  the  limits  of  a  single 
genus. 

(21 6.)  The  station  of  Lamarck's  genus  Calyp- 
tr^a  is  fully  determined  by  the  structure  of  his  Sto- 
matella  duplicata,  since  both  form  an  obvious  passage 
to  the  Trochidcp,  by  showing  the  first  developement  of 
a  central  pillar.  Lamarck's  observations  upon  this 
interesting  group,  which  contains  many  natural  sub- 
genera, appear  to  us  characteristic  of  that  accurate  per- 
ception, almost  intuitive,  of  natural  afl!inities  and 
relations  which  characterised  all  his  writings  before  his 
unfortunate  blindness,  —  a  rare  talent  of  discrimination, 
which,  as  it  has  been  justly  observed  by  others,  places 
him,  in  this  respect,  far  above  even  the  author  of  the 
Regne  Animal.  Although  he  had  not  the  advantage 
of  being  acquainted  with  the  animal,  made  known  to 
us  by  the  unpublished  drawings  of  Guilding*  (of 
which  the  annexed  cut  is  a  copy,  fig.  42.),  he  con- 
sidered this  genus,  not  related  (by  affinity)  to  Patella, 
but  that  its  incipient  spire  and  pillar  indicated  a  struc- 
ture approaching  to  that  of  Trochus.  He  erred,  appa- 
rently, in  carrying  this   theory  too   far,   by   supposing 

*  The  typical  form  is  probably  C.  Chinensis,  the  species  here  figured. 


234 


SHELLS    AND    SHELL-FISH. 


PART  I. 


that  his  C.  trocMformis  would  he  hetter  placed  in  that 
family.  But  even  the  errors  of  such  a  man  are  as 
lights  to  others ;  for  when  douhts  exist  as  to  the  limits 
of  a  genus,  we  may  be  perfectly  sure  of  the  passage, 
and  that  both  genera  are  natural.  On  the  other  hand, 
if  we  look  to  the  resemblance  between  Patella  and 
CalyptrcBa  as  analogical,  these  conflicting  opinions  are 
at  once  reconciled  :  both  are  cup-shaped,  pyramidical, 
and  with  the  apex  almost  central ;  and  that  both  stand 
opposite  to  each  other  in  their  respective  circles,  the 
intelligent  reader  will  perceive  if  he  brings  these  fa- 
milies into  comparison. 

(217.)  The  next  group,  which,  from  a  consideration 
of  the  animal,  we  have  here  named  Cheltnotus,  cor- 
responds, in  some  measure,  to  Sigaretus  of  authors. 
We  find  it  impossible,  however,  to  understand  this 
group.  It  has  been  customary  to  place  in  Sigaretus 
nearly  all  those  ear-shaped  shells  of  the  same  form  as 
Stomatia,  but  which  are  not  perlaceous,  without  a 
knowledge  of  their  animals,  or,  even  when  that  was 
obtained,  without  a  due  regard  to  the  differences  they 
exhibited.  We  mention  this,  not  as  conveying  censure, 
but  as  the  probable  reason  why  we  cannot  unravel  this 
exceedingly  intricate  question.  This  has  partly  arisen, 
strange  as  it  may  appear,  from  the  new  light  thrown 
upon  the  JVaticce  by  Guilding.  The  beautiful  delinea- 
tions he  has  made  of  the  animal  of  a  typical  species, 
shows   that  it   is   almost  an  internal  shell,  or  at  least 


CHAP>  VIII.        SIGARETUS,   AND   ITS  PROTOTYPES.  235 

SO  far  as  that  its  circumference  is  fitted  into  a  fleshy 
rim.  The  aspect  of  Quoy's  Cryptostoma  again,  and  of 
Blainville's,  are  much  the  same  ;  and  neither  of  these 
agree  with  the  delineation  of  the  animals  of  De  Blain- 
ville's Sigaretus,  Vetulina,  or  Coriocella.  In  the  pre- 
sent difficulties,  in  short,  which  surround  this  question, 
we  shall  leave  it  for  the  investigation  of  others :  our 
impression  is,  that  part  of  the  Sigareti  of  authors  be- 
long to  the  Naticidce,  and  part  to  this  group  ;  and 
that  these  can  only  be  determined  by  the  structure  of 
their  animals.  In  the  meantime  we  have  no  great  hesita- 
tion in  considering  De  Blainville's  Coriocella  and  Velutina, 
in  conjunction  with  Quoy's iS'/^are^  de  Tonga,  as  sub-ge- 
nera of  that  genus  which  intervenes  between  Calyptrfjea 
and  Crepidula,  and  which  we  provisionally  call  Cheli- 
NOTus,  from  the  resemblance  which  the  typical  forms  bear 
to  the  back  of  the  tortoise.  The  animals  of  all  these  have 
two  short,  thick,  cylindrical  tentacula  ;  the  eyes  being 
at  their  base,  and  either  sessile,  as  in  Coriocella,  or  at 
the  tip  of  short  peduncles  (which  are  united  to  the  ten- 
tacula), as  in  Chelinotus*  We  believe,  also  (judging 
only  from  his  figure),  that  De  Blainville's  Sigaretus  con- 
vea:usf  belongs  also  to  this  group,  since  the  animal 
merely  differs  from  the  Coriocella  and  Chelinotus  in  not 
having  the  anterior  part  of  its  mantle  forked,  and  being 
very  little  larger  than  its  shell,  which  thus  becomes 
external.  As  for  the  shells  themselves  of  these  genera, 
they  seem  to  be  all  of  one  form,  precisely  like  that  of 
Vitrina,  which  they  obviously  represent :  hence  they 
are  not  of  primary  importance  in  determining  the  ques- 
tion. As  for  the  Sigareti  of  Lamarck,  Sowerby,  &c., 
we  suspect  that  when  their  animals  become  known,  they 
will  turn  out  to  belong  to  the  NaticidcE,  since,  so  far 
as  the  shells  are  concerned,  we  have  a  most  perfect 
series  by  which  they  seem  to  be  connected  with  the 
Natica  mamilla  of  authors  ;  while  Cryptostoma  may 
possibly  be  the  tectibranchian  type  of  that  family,  just 

*  Si'garet  de  Tonga,  Quoy,  Voy.  d'Astrolabe,  pi.  66.  bfs,  figs.  4 — 8. 
+  Manuel,  pi.  xlii.  fig.  2.  2  a. 


236 


SHELLS    AND    SHELL-FISH.  PART  I. 


as  Chelinotus  is  of  this  :  such,  at  least,  are  our  present 
impressions  on  the  relations  of  these  perplexing  forms. 
Our  object,  in  all  cases  where  we  cannot  analyse,  is  to 
state  difficulties,  not  to  smooth  them.  The  present 
instance  is  one  of  the  few  groups  we  are  compelled, 
from  this  cause,  to  leave  in  uncertitude.  The  reader 
will  remember  that  the  same  difficulty  has  occurred  in 
regarding  the  Bailee.  Now,  both  of  these  are  analogous 
groups,  and,  with  the  NaticcB,  are  all  representatives  of 
the  naked  order  Tectibranchia.  This  will  be  ap- 
parent on  looking  to  the  opposite  columns,  the  contents 
of  which  follow  each  other  perpendicularly,  while  the 
analogies  are  expressed  horizontally. 

(218.)  A  chapter  would  be  scarcely  sufficient  for  the 
full  explanation  of  the  innumerable  relations  implied  in 
this  table  ;  we  must  therefore  confine  our  attention  to 
that  line  which  contains  the  analogical  representations  of 
the  Tectibranchia.  All  these  turn  out  to  be  slug-like 
animals,  with  shells  either  larger  than  their  bodies,  or 
more  or  less  capable  of  being  concealed  by  the  mantle  : 
they  are  all  free,  that  is,  they  have  the  full  power  of 
locomotion  ;  their  shells  have  few,  if  any,  voluties  ;  of 
a  thin  and  delicate  substance  in  most,  but  rarely  sculp- 
tured ;  never  rough,  and  generally  smooth  and  polished. 
But  what,  perhaps,  is  the  most  remarkable  feature 
running  through  the  majority,  is  the  striking  resemblance 
they  bear  to  tortoises,  not  merely  in  the  oval  depressed 
form,  and  often  coriaceous  covering  of  their  back,  but 
that  this  part  should  often  be  divided  into  angular  or 
hexagonal  plates,  precisely  analogous  to  those  reptiles. 
Hence  the  expressive  name  of  Chelisoma,  given  by 
Mr.  Broderip  to  the  type  which  represents  the  Cyclo- 
branchia,  while  the  back  of  our  Chelinotus  seems  as 
if  it  was  entirely  covered  with  a  shell  divided  into  regular 
series  of  hexagonal  plates.  Even  the  shells,  if  such 
they  may  be  called,  of  the  typical  Tectibranchia  (as 
Aplysia,  &c.)  resemble  the  thin  horny  layers  on  those 
of  tortoises  ;  while  the  BuUcf,  if  they  really  belong  to 
the  Cyprcea,  so  perfectly  resemble  these   sea-slugs,  that 


CBAP.   VIII. 


ANALOGIES    OF    TECTIBRANCHIA. 


237 


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(A 

238  SHELLS    AND    SHELL-FISH.  PART  I. 

we  know  not^  at  present,  the  limits  between  the  two. 
We  could  extend  these  analogies  into  the  vertebrated 
animals  ;  for  they  are  not  only  manifested  among  the 
reptiles  by  the  Clielonides  or  turtles,  but  by  the  arma- 
dillos, in  the  order  of  ruminating  quadrupeds,  the  Cas- 
sidcB,  or  tortoise  beetles,  among  the  coleopterous  insects ; 
and,  in  short,  throughout  the  whole  animal  kingdom. 

(219.)  Leaving,  therefore,  the  true  affinities  of  the 
Sigareti  of  authors  undetermined,  we  may  proceed  to 
the  genus  d'epidula  as  the  last  we  place  in  the  present 
family.  \^e  know  not  by  what  form,  if  any,  it  is  con- 
nected to  Chelinotus,  but  its  affinity  on  one  side  to  Na- 
vicella,  and  consequently  to  the  nerits,  has  been  long  ad- 
mitted ;  while  to  Haliotis  it  is  as  obviously  connected  by 
means  of  Crep,  aculeata,  and  such  other  ear- shaped  spe- 
cies as  have  defined  spiral  whorls  placed  on  one  side  of 
the  shell,  as  in  the  HaliotidcB.  Hence  it  follows  that  Cre- 
pidida  stands  at  one  side  of  the  circle  of  the  Haliotidce, 
connecting  them  with  the  Naticidce,  and  Cnlyptrcea  at  the 
other,  connecting  them  with  the  Trochidcs  ;  it  .'follows, 
therefore,  that  they  cannot  be  united  by  affilnity,  except 
indeed  on  our  theory,  that  the  three  aberrant  groups 
always  form  a  circle  of  their  own. 

(220.)  Our  fifth  and  last  family  is  that  of  the 
JVaticidcB,  or  nerits,  consisting  of  those  genera  whose  in- 
habitants are  not  furnished,  like  the  Turbidce,y,viih  a  pro- 
boscis-formed mouth,  and  eyes  placed  upon  their  antennae, 
but  whose  mouth  is  like  that  of  the  generality  of  shell- 
fish belonging  to  this  tribe,  and  whose  eyes,  where  they 
exist,  are  at  the  base  of  their  tentacula.  The  animal  of 
one  of  the  typical  Naticidce  has  been  beautifully  drawn 
by  Guilding,  and  is  here  copied  (Jig.  43.)  ;  it  is  a  most 
extraordinary  looking  creature.  The  whole  family  differs 
from  the  Trochidce,  moreover,  in  having  no  lateral  fila- 
ments; and  in  the  form  of  their  lips,  eyes,  &c. ;  and  from 
the  HaliotidcB,  in  all  that  respects  the  animals,  as  well  as 
their  shell.  For  reasons,  however,  which  we  have  just 
before  this  detailed,  this  is  the  only  family  whose  analysis 
we  find  it  impossible  to  complete  ;   this  originates  in  the 


CHAP.   VIII. 


THE  NATICID.E,   OR  NERITS. 


239 


incertitude  regarding  the  many  earlike  shells  belonging 
or  related  to  the  genus  Sigaretus  of  authors^  but  of  whose 
animals  we  know  little  or  nothing.  The  reader  will, 
therefore,  understand  that  the  only  groups  we  consider 
to  be  natural  in  the  following  arrangement,  are  those  of 
the  NeritincB  and  the  NaticincE;  the  three  others  being 
merely  conjectural.  If  the  animal  of  Cuvier's  Sigaretus 
is  like  that  of  De  Blainville's,  we  should  thus  refer  it  to 
the  group  which  contains  Chelinotus  ;  but  we  strongly 
suspect  that  the  shells  of  the  Sigareti  figured  by  Sowerby* 
all  belong  to,  and  form  the  typical  group  of,  the  present 
family  :  Lamarck's  Natica  constitutes  the  second  ;  and 
the  Linnaean  nerits  the  third  :  the  other  two  may  pro- 
bably be  represented  by  the  CryptostonifV  of  Blainville 
and  Quoy  ;  and  the  fifth,  which  forms  the  passage  to  the 
TurhidcB,  either  by  Lacuna,  Turton,  or  more  probably 
by  such  long-spired  types  as  Truncatella,  Lowe.  Of  all 
these,  as  shells,  it  may  be  said  generally,  that  they  are 
globose  and  turbinate ;  the  spire  being  always  very  slightly 
developed,  the  aperture  large  and  semilunar,  and  the 
operculum,  where  it  exists,  either  shelly  or  horny.  They 
are  moderate-sized  shells,  mostly  marine,  and  are  never 
perlaceous.  In  the  NeritincE,  which  approach  nearest 
to  the  Haliotida,  the  spire  is  sometimes  nearly  or  quite 
obsolete ;  but  in  the  NaticincB  it  is  more  developed  and 
ventricose.  The  JVerilincs,  by  the  teeth  on  their  pillar, 
and  excessively  short  spire,  represent  the  Volutidce  ;  and 
Cryptostoma,  the  Limacince,  or  terrestrial  slugs.     What 

*  Genera  of  Shells. 


240 


SHELLS    AND    SHELL-FISH. 


PART  I. 


the  shells  of  these  latter  really  are,  we  know  not ;  but  we 
have  two,  very  thin  and  hardly  opaque,  which,  judging 
from  his  figures,  we  suspect  are  of  Quoy's  Cryptostoma  : 
they  are  as  brittle  as  those  of  Vitrina,  but  are  of  that 
semitransparent  whiteness  which  shows  they  must  be 
internal  shells,  and  they  have  no  sculpture  whatever. 
As  to  the  Sigaretus  cancellatus  of  Lamarck,  it  is  mani- 
fest nothing  can  be  advanced  beyond  mere  conjecture 
until  the  animal  is  known.  Of  all  these,  therefore,  the 
NaticincB  and  the  Neritince  are  the  only  sub-families 
which  can  safely  be  relied  upon  as  unquestionable  ;  yet 
even  their  genera  cannot  be  demonstrated  with  that  pre- 
cision that  could  be  wished. 

(221.)  The  intimate  connection  between  this  family 
and  the  Turhidce  is  too  evident  to  require  any  demon- 
stration. Thus,  then,  do  we  return  to  the  latter  group, 
and  the  great  circle  of  the  phytophagous  Gasteropoda  is 
rendered  complete.  On  looking  to  its  component  parts 
or  families,  and  to  those  of  the  zoophagous  or  carnivo- 
rous tribe,  we  find  them  representing  each  other  in  this 
manner :  — 

Analogies  of  the  Phytophagous  and  Carnivorous 

Gasteropoda. 


Families  of  the 
Phytophaga. 

Helicid*;. 
Trochidje. 

Haliotid^. 


Naticid^. 


TuRBIDIDjE. 


■1 


Analogies. 

Typical  of  their  respective  tribes. 

Sub-typical. 

Tentacula    very    short,     sessile; 
shell  with  the  body-whorl  ex- 
cessively large;  the  spire  very! 
short,  and  scarcely  raised. 

Animal,  when  crawling,  larger" 
than  its  shell,  which  is  smooth, ( 
and  generally  polished;  spire ( 
nearly  or  quite  obsolete. 

Animal  with  a  proboscis-formed") 
mouth,  and  a  resj>iratory  si- f 
phon;  eyes  placed  on  the  sides  1 
of  the  tentacula.  j 


Families  of  the 
Zoophaga. 

MURICID^ 
TURBlNELLIDi;. 

V0LUTID;E. 


CypRJiiD^. 


Strombid*. 


There  is  every  reason  to  suppose,  from  the  three  last 
analogies,  that  the  two  first  will  rest  also  upon  the  struc- 
ture of  the  animals,  and  not  upon  their  shells  ;  but  it  un- 
luckily happens  we  are  totally  ignorant  of  that  inhabiting 


CHAF.    IX.  SCUTIBRANCniA^   OR    LIMPETS.  241 

the  typical  Turhinellidce,  so  that  it  is  impossible  to  de- 
termine what  are  its  relations  to  the  TrocMdce.  In  the 
present  state  of  malacology,  our  only  surprise  should  be 
that  so  much  may  be  effected,  and  so  many  land-marks 
planted,  with  such  very  scanty  materials. 


CHAP.  IX. 

ON    THE    ABERRANT     TRIBES     OF    THE     GASTEROPODA, NAMELY, 

THE    SCUTIBRANCHIA,    OR    LIMPETS  ;    THE    CYCLOBRANCHIA,    OR 
CHITONS  ;    AND  THE  PTEROPODA,  OR  CRYSTAL-SHELLS. 

(222.)  The  immense  superiority  in  extent  and  multi- 
plicity of  types,  which  the  phytophagous  and  carnivorous 
gastropods  possess  over  all  the  other  Testacea,  not  to 
mention  the  superior  interest  attached  to  them  by  con- 
chologists  and  collectors,  have  induced  us  to  devote  the 
greater  part  of  our  volume  to  their  illustration.  Our 
space  being  limited,  we  have  therefore  no  other  resource 
but  to  abridge  our  remaining  survey  as  much  as  possible. 
(223.)  The  first  of  our  aberrant  tribes  is  composed 
of  the  ScuTiBRANCHiA,  Or  limpets  ;  in  extent,  it  is  little 
larger  than  one  of  the  least  families  of  the  spiral  shell- 
fish: they  may  be  almost  termed  sedentary  or  fixed  ;  for 
although  some  have  the  power  of  locomotion,  it  is  so 
limited  that  their  shell  often  assumes  the  contour  of  the 
spot  where  they  have  remained.  In  the  arrangement  of 
their  branchia,  and  the  form  of  their  bodies,  they  may 
almost  be  called  testaceous  DoridtE,  at  least  so  far  as  the 
typical  species  are  concerned.  The  passage  to  this  tribe, 
from  the  Haliotidcp,  or  ear-shells,  is  rendered  perfectly 
easy  and  natural,  whether  we  regard  the  want  of  a  spire  in 
Crepidulaor  the  patelliform  shape  oi Calijptrcea.  We  have 
now  arrived  at  the  last  division  of  univalve  shells,  where 
the  structure  is  so  simple  that  the  sheUy  part  of  these 

B 


24-2  SHELLS    AND    SHELL-FISH.  PART  I. 

animals  merely  consists  of  a  cup-shaped  protection,  with- 
out the  least  vestige  of  a  spire,  a  whorl,  or  any  internal 
support.  The  peculiarities  of  the  animals  have  already 
been  stated,  and  as  those  of  the  shells  will  be  subsequently 
defined,  Ave  may  at  once  proceed  to  a  short  statement 
of  their  relations  and  analogies.  The  whole  are  consti- 
tuted of  the  following  divisions,  which  may  be  termed 
genera.  1.  Fiss urella,  h&\mg  an  oval  perforation  on 
the  apex  or  summit  of  the  shell.  2.  Emarginula,  where 
the  perforation  is  a  narrow  slit.  3.  Hipponyx,  with  the 
shell  entire,  but  reposing  on  a  spurious  flattened  valve. 
4.  Pedicularia,  an  entirely  new  genus.  And,  5.  Patella, 
having  a  simple  cup-shaped  shell,  without  any  aperture 
or  basal  support.  The  three  last  are  sedentary,  and 
constitute  the  aberrant  genera,  the  two  former  being  the 
typical.  A  very  rapid  survey  of  these  groups  is  all  that 
we  can  give  to  them. 

(224.)  The  genus  Fissurella  has  the  perforation  on 
the  top  of  the  shell  very  much  resembling  a  keyhole. 
This  aperture  is  for  the  purposes  of  respiration,  as  the 
water  thus  communicates  to  the  branchial  cavity,  which 
is  placed,  something  like  that  of  Doris,  on  the  fore  part 
of  the  back.  The  eyes,  the  mouth,  and  tentacula  are 
very  like  those  of  the  Haliotidce  ;  and  the  margin  of  the 
foot  is  also  edged  with  short  filaments.  The  shell,  ac- 
cording to  Cuvier  and  Lesson,  is  placed  in  the  middle 
of  the  back,  but  does  not  cover  it ;  so  that  we  can  scarcely 
suppose  it  is  fixed  to  rocks,  like  the  limpets.  The  mus- 
cular impressions  in  some  of  these  shells,  joined  to  their 
outward  differences,  intimate  the  existence  of  sub-genera, 
some  of  which  we  have  ventured  to  characterise  ;  Ave 
should  not,  perhaps,  have  done  this,  as  the  species  are  so 
few,  had  not  most  of  those  in  the  adjoining  genus  been 
already  named. 

(225.)  The  Emarginula,  from  the  very  slight  notice 
given  of  them  by  Cuvier,  do  not  appear  to  differ  more  in 
their  animal,  than  iii  their  shell,  from  the  last.  This 
difference,  hoAv-ver,  is  quite  sufficient  to  constitute  them 
a  genus.     Thj  aperture  in  the  shell    (which  is  more 


CHAP.   IX.  SCUTIBRANCaiA,    OR    LIMPETS.  243 

conic)  is  not  oval,  but  forms  a  very  narrow  slit  or  cleft, 
the  position  of  which  indicates  the  particular  situation 
of  the  branchial  cavity.  In  the  typical  species,  this  slit 
is  at  the  base ;  in  the  sub-genus  Cemaria  Leach,  it  is 
in  the  apex  ;  while  in  Rimiila  it  is  central  between  the 
apex  and  the  margin.  The  most  aberrant  type  is  Par- 
mophoriis,  where,  as  in  all  the  tectibranchial  types,  the 
animal  is  much  larger  than  the  shell,  which  thus  be- 
comes partly  internal  ;  hence  there  is  only  a  slight 
emargination  on  the  margin.  Our  new  sub-genus  He- 
mitonia opens  the  passage  between  this  and  Emarginula  ; 
and  thus  the  whole  form  a  circle.  The  animal,  like  that 
of  Fissurella,  has  the  margin  of  the  foot  fringed  with 
filaments,  and  the  eyes  pedunculated,  but  at  the  base  of 
the  tentacula.  Cuvier  says  the  mantle  envelopes  and 
covers  a  great  part  of  the  shell ;  and  this  is  shown  by 
Riippell  to  be  the  case  also  in  Parmophorus,  but  to  a 
greater  extent. 

(226.)  HippoNYx  is  one  of  the  most  remarkable  of 
the  patelliform  shells :  it  is  cup-shaped,  like  Emar 
ginida,  but  has  no  fissure  :  it  may  be  almost  termed  a 
bivalve,  since  it  forms  a  flat,  thin,  calcareous  plate,  which 
covers  that  part  of  the  rock  on  which  the  upper  valve, 
or  true  shell,  reposes  ;  this  latter  so  much  resembles  a 
limpet,  that  it  can  only  be  known  by  its  horseshoe 
muscular  impression :  the  common  species  are  small, 
and  generally  whitish.  The  animal  figured  by  Mr. 
Quoy  has  the  mouth  shaped  like  a  short  proboscis,  to- 
tally different  from  that  of  the  Trochidce,  near  to  which 
some  authors  approximate  it ;  the  mantle  is  not  fringed, 
and  the  eyes  and  tentacula  are  like  those  of  Einarginula. 
Several  recent  species  from  warm  countries  are  now 
known,  and  a  few  fossil  ones.  The  sub-genus  Capulis, 
which  has  not  this  basal  valve,  seems  to  connect  Hip- 
ponyx  with  Emarginula,  —  which  latter  it  resembles  in 
the  cup-shaped  form  of  its  shell.  The  analogy  of  this 
genus,  in  their  shells,  to  the  bivalve  Branchiopoda,  is 
particularly  remarkable. 

(227.)  The  genus  Patella  stands   at  the  opposite 

B  2 


244  SHELLS    AND    SHELL-FISH.  PART  I. 

side  of  the  circle  we  are  now  tracing,  and  consists  of  all 
those  simple  cup-shaped  shells  which  have  a  defined  apex 
or  top,  but  without  any  basal  or  internal  support.    They 
adhere  to  rocks,  and  by  their  broad  and  fleshy  foot  retain 
such  a  firm  hold  as   not  to  be  separated  without  great 
art  or  violence.     The  animal  very  much  resembles  that 
oi  Hipponyx ;  for  Cuvier  says  it  has  a  short  and  thick 
snout,  two  distinct  and  pointed  tentacula,  and  the  eyes 
placed  at   the  base.       The  most  important  sub-genus 
yet   determined  is   Siphonana  Sow.,  which,   with   that 
inconsistency  and  violation  of  all  natural  affinities  which 
pervades  the  greater  part  of  this  class,  as  exhibited  in 
the  Regne  Animal,  is  actually  placed  in  a  different  order, 
between  Calyptrcea  and   Sigaretus  !    Every  one  accus- 
tomed to  contemplate  the  beautiful  order  and  gradation 
of  nature,  must  be  shocked  at  such  a  violation  of  natural 
affinity  as   this  arrangement  exhibits.     It   is   the  more 
inexcusable,  because  it  is  neither  sanctioned  by  any  re- 
semblance whatever  between  the  shells  or  their  animals 
of  the  genera  thus  confusedly  mixed.     Slphonaria,  in 
short,    is    that  link  which  connects  the  Scutihrunchia 
with  the  Cyclobranchia ;  for,  like  these  latter,  according  to 
Cuvier's  own  showing,  "  the  tentacula  seem  to  be  want- 
ing, the   head   being   merely  furnished  with   a   narrow 
veil ;"  so  that,  if  these  organs  really  exist,  they  must  be 
but  mere  vestiges.     Here,   then,   is   probably    the  last 
form  of  the  Scutihranchia ;  and  it  occurs  exactly  at  that 
point  of  the  circle  which,  from  theory,  could  be  next  to 
the  Cyclobranchia. 

(228.)  But  there  is  yet  another  form  to  be  added : 
this  is  our  new  genus  Pedicularia  (^(jt.  44.),  which 
appears  never  to  have  been  described  by  any  writer.  In 
its  somewhat  patelliform  shape  it  resembles  a  Patella  ; 
yet,  although  always  oval,  its  form  is  irregular,  since 
its  circumference  is  adapted  to  the  inequalities  of  the 
substance  to  which  the  animal  adheres  :  hence,  to  an 
inexperienced  eye,  the  margin  would  appear  broken  :  its 
substance,  however,  is  strong,  like  that  of  a  Hip- 
ponyx,    from   which    and    from    Patella    it    essentially 


CHAP.   IX.  SCUTIBRANCHlAj    OR    LIMPETS. 


245 


differs  in  having  a  callous  prominent  rim  placed  longi- 
tudinally on   one  side  only   of  the   inner   surface,  and 

to  which  the  principal  muscle  is  pro- 
bably attached :  there  is  no  regular 
apex,  but  merely  a  rudimentary  indi- 
cation of  one, — one  side  of  the  shell 
being  more  gibbous  than  the  other  ; 
so  that,  if  this  faint  indication  of  a  vo- 
lution had  formed  an  apex,  it  would 
have  been  longitudinal,  or  on  the  late- 
ral sides  of  the  shell, — and  not  central,  as  in  Patella.  The 
annexed  figures  will  illustrate  this  description,  and  show 
the  irregularity  of  form  in  one  and  the  same  species.  We 
found  all  these  adhering  to  coral  fished  up  on  the  coast  of 
Sicily,  so  far  back  as  1 807 ',  and  a  few  specimens,  if  we 
mistake  not,  were  given  to  our  friend  Dr.  Leach,  for  the 
British  Museum.  It  is  perfectly  analogous  to  the  parasitic 
genus  Coccus  among  insects;  and,  indeed,  much  more 
resembles  them,  or  the  internal  shell  of  some  unknown 
tectibranchian  moUusk,  than  any  thing  else.  An  approxi- 
mation is  made  to  this  genus  by  certain  small  limpets, 
whose  apex,  from  being  lateral,  makes  them  also  inequi- 
lateral shells  :  of  course,  we  know  nothing  of  the  animal ; 
but,  from  the  nature  of  the  shell,  it  must  be  perfectly 
sedentary,  as  it  embraced  the  coral  most  closely. 

(229.)  The  Cyclobranchia,  or  Chitones,  are  known 
at  once  by  their  shells.  They  differ  from  all  the  gastro- 
pods yet  noticed  *,  in  being  quite  destitute  of  tentacula, 
—  these  organs  being  supplied  by  a  membranaceous  veil 
round  the  mouth :  the  mantle,  also,  unlike  that  of  the 
Patellce,  is  always  exposed,  and  forms  the  circumference 
of  that  part  by  which  the  animal  adheres  :  it  is  therefore 
externally  coriaceous,  and  is  covered  for  its  protection 
by  minute  scales  resembling  shagreen,  and  often  with 
spines  or  setaceous  hairs  ;  and  on  each  side,  underneath, 
are  the  lamellar  branchia  :  this  arrangement  of  the  or- 
gans of  breathing   gives  the  name  to  the  tribe.     The 

*  Except  Herpa  among  the  Limachue,  which  is  the  cyclobranchian  type 
of  the  HelicidiE. 

B    3 


246  SHELLS    AND    SHELL-FISH,  PART  I. 

testaceous  part  of  the  animal  consists  of  a  row  of  sym- 
metrical scales^  generally  imbricate,  or  reposing  on  each 
other  transversely  along  the  middle  of  the  back  ;  but 
sometimes_,  as  in  Chitonellus,  these  valves  are  widely 
separated.  The  only  naturalist  who  has  effectually  in- 
vestigated these  shell-fish,  is  our  late  regretted  friend 
Guilding ;  and  to  his  admirable  paper  upon  them,  we 
are  indebted  both  for  their  natural  arrangement,  and  the 
following  notes  on  their  manners  when  living  : — "These 
animals  frequent  the  rocks  and  stones  of  the  sea  coast, 
and  are  distributed  nearly  over  the  whole  globe.  Many 
species  are  constantly  under  water ;  while  others  ascend 
even  above  high  water  mark,  spending  the  day  exposed 
to  the  hottest  sun,  or  resting  in  spots  occasionally 
moistened  by  the  rude  and  restless  surf.  In  Chitonellus 
and  Cryptoconchus,  there  are  certain  minute  organs  on 
the  zone,  which  bear  a  strong  resemblance  to  the  spi- 
racula  of  annulose  animals.  They  seem  to  feed  en- 
tirely by  night.  Though  they  remain  stationary  during 
the  day,  yet  when  disturbed  they  will  often  creep  away 
with  a  slow  and  equal  pace  ;  sometimes  sliding  sideways, 
and  creeping  under  rocks  or  stones  for  concealment. 
If  accidentally  reversed,  they  soon  recover  their  posi- 
tion by  violently  contorting  and  undulating;  and  for 
defence,  they  sometimes  roll  themselves  up,  like  the 
woodlice."*  Although  only  two  or  three  small  species 
are  found  in  Europe,  there  are  numerous  large  ones 
from  the  tropical  latitudes,  particularly  the  coasts  of 
Chili  and  Peru. 

(230.)  The  Tectibranchia  constitute  the  last  group 
in  our  arrangement  of  the  Gasteropoda.  In  it  we  in- 
clude all  those  naked  testaceous  mollusks,  whose  shell, 
when  it  exists,  is  either  rudimentary  or  partly  con- 
cealed by  the  lobes  of  the  mantle;  and  whose  branchia, 
in  the  form  of  leaves,  are  arranged  either  on  one  or 
both  sides  of  the  body,  or  on  the  back,  but  in  all  cases 
concealed  or  covered  either  by  the  edge  of  the  mantle 
or  by  a  thin  shell.     We  do  not  think  that  these  animals 

*  Zoological  Journal,  v.  29. 


CHAP.    IX.  CYCLOBRANCHIA. TECTIBRANCHIA.         247 

have  any  degree  of  affinity  with  the  IVudibranchia, 
whose  gills  are  invariably  exposed,  and  arranged  sym- 
metrically. All  are  marine,  and  crawl  on  their  belly  ; 
but  the  major  part,  from  having  the  lobes  of  the  mantle 
dilated,  are  likewise  capable  of  swimming.  Nevertheless, 
they  are  thick,  unsightly  creatures, —  resembling,  when 
caught,  shapeless  lumps  of  flesh ;  for  the  tentacula, 
where  they  exist,  are  short ;  the  shell  (if  present)  is 
hid  in  the  mantle ;  and  it  is  difficult  to  know,  at  first,  at 
which  extremity  the  head  is  placed.  They  cannot  be 
preserved  effectually  in  spirits ;  but  by  being  placed  in 
sea  water,  when  first  caught,  they  soon  begin  to  crawl, 
and  exhibit  their  true  form.  The  annexed  sketch  of  our 
Aplysia  Sicula  {Jig.  45.),  taken  from  the  living  animal. 


wiU  give  a  good  idea  of  that  genus :  it  has  the  power, 
like  many  other  species,  of  emitting  a  copious  black  or 
purple  fluid  when  caught,  like  some  of  their  prototypes 
the  Cephalopoda,  for  the  purpose  of  discolouring  the 
water,  and  eluding  their  enemies. 

(231.)  The  Tectibbanchia,  even  from  the  little 
yet  known  of  them,  appear  to  form  a  most  natural 
group,  in  which  the  circular  succession  of  the  five 
types,  and  the  analogies  they  bear  to  the  conterminous 
tribes,  may  be  distinctly  traced.  The  variation  in  the 
form  and  position  of  the  branchia,  although  quite  in- 
sufficient to  remove  the  aberrant  types  from  Aplysia,  is 
yet  of  much  importance  in  determining  the  primary 
divisions.    Thus,  in  the  Bullince  and  the  Aplysiance,  the 

H.  4 


248  SHELLS    AND    SHELL-FISH.  PART   I. 

gills  are  on  the  back,  with  long  pectinations  on  one 
side  :  in  the  first  they  are  covered  by  an  oviform  shell, 
and  in  the  latter  by  a  convex  plate,  resembling  half  a 
bivalve.  In  the  three  aberrant  divisions,  however,  the 
branchia  are  lateral.  Phyllidea  has  them  on  both  sides  ; 
Pleurobranchus  and  Gasteropteron,  on  the  right  only  ; 
and,  as  Cuvier  says  that  this  latter  genus  "  appears  to 
be  an  Akera  with  the  foot  developed  into  broad  wings," 
we  consequently  return  again  to  the  Bullince.  If  we 
look,  on  the  other  hand,  to  the  presence  or  absence  of 
the  testaceous  covering,  the  same  circular  course  of  the 
groups  can  be  demonstrated.  The  pre-eminent  type, 
seen  in  the  genus  Bulla,  has  the  shell  so  perfect  as 
sometimes  to  be  capable  of  receiving  the  greater  part  of 
the  animal,  and  it  is  always  more  or  less  convolute.  In 
the  sea  hares  or  Aphysiance,  however,  it  is  a  mere  ru- 
diment, like  one  half  of  a  bivalve  shell;  while  in  the 
three  aberrant  types,  even  this  vestige  is  totally  wanting. 
Some  of  Cuvier's  genus  Akera,  he  observes,  have  no 
shell  whatever,  or  only  a  vestige  of  one,  yet  with  the 
mantle  of  Bulla  ;  and  as  he  insists,  in  another  place,  on 
this  genus  being  the  closest  to  Gasferopteron,  we  come 
to  the  same  results  as  by  studying  the  variation  of  the 
branchia.  The  argumentum  ad  verecundiam  may  thus 
be  advantageously  employed,  though  we  generally  prefer 
resting  our  theory  on  the  simple  facts  brought  before 
the  reader. 

(232.)  And  yet,  although  there  is  evidently  a  cir- 
cular disposition  among  the  Tecti branchia,  and  a  strong 
affinity  to  the  Cyclohraiichia  on  one  side,  and  to  the 
Pte?'opoda  on  the  other,  their  affinity  with  the  Gas- 
teropoda  is  not  so  evident, —  at  least,  if  we  consider  the 
BullcB  as  standing  at  the  head  of  the  tribe.  This 
point,  however,  cannot  be  well  decided,  until  we  know 
the  animals  of  such  shells  as  Bulla  7^aucum,  Aplustra 
pulchella* ,  Sec.  There  can  be  no  doubt,  that  between  an 
animal  which  can  recede  entirely  within  its  shell,  and  one 
which  envelopes  it  (as  Akera,  &c.),  there  must  be  many 

*  Bulla  aplustrc  Linn. 


CHAP.  IX.  TECTIBRANCHIA.  24<9 

essential  differences.  Lamarck  has  judiciously  sepa- 
rated these  into  two  groups^  to  the  first  only  of  which 
he  retains  the  old  name  of  Bulla  :  some  of  these  may, 
possibly,  be  connected  to  the  aberrant  VolutidiE  ;  while 
others,  by  uniting  with  Akera,  will  open  a  passage  to 
the  Cephalapoda  by  means  of  G aster opteron.  At  all 
events,  the  situation  of  the  Tectibranchia  is  clearly 
intermediate  between  the  Gasteropoda  and  the  Ce- 
phalopoda, 

(233.)  The  Phyllidin^e,  as  Lamarck  has  already 
shown,  evidently  connects  the  Cyclohranchia  to  the 
Aplysia,  or  sea-hares  ;  hence  its  general  form  is  that  of 
a  Chiton,  being  oblong  oval,  but  without  any  testaceous 
covering.  The  mantle  does  not  appear  divided,  but 
covers  the  back  like  a  shell,  and  is  usually  of  a  strong 
coriaceous  substance :  there  are  two  small  tentacula, 
shaped  as  in  Doris,  on  the  upper  surface ;  and  two 
others,  still  smaller,  beneath,  on  the  sides  of  the  mouth, 
which  Cuvier  says  "is  a  small  proboscis;"  but  this 
does  not  appear  in  Riippell's  figure  of  P.  pustulosa  * , 
which  was  taken  from  the  life.  The  branchia  are  in  the 
form  of  two  long  leaves  or  pectinated  processes,  placed 
on  each  side  of  the  body,  under  the  edge  of  the  mantle, 
for  its  whole  length.  The  anus  is  on  the  hind  part, 
and  the  genital  orifice  forward,  under  the  right  side. 
In  the  sub-genus  Diphyllidea,  the  branchia  are  the 
same;  but  the  anterior  part  is  more  narrowed,  and  the 
second  pair  of  tentacula  are  reduced  to  tubercles. 
These  animals  are  not  numerous,  and  are  almost  con- 
fined to  the  Eastern  Ocean. 

(234.)  In  Aplysia  t,  the  typical  characters  already 
mentioned  begin  to  appear.  These  animals  have  the 
appearance  of  a  neck.  The  upper  tentacula  are  shaped 
exactly  like  those  of  a  hare,  whence  the  common  name 
of  Sea-hares,  given  to  these  animals  in  most  countries 

*  Ruppell,  Atlas  i.  pi.  11.  fig.  1. 

t  A  very  costly  work  by  M.  Sander  Rang  and  DeF^rus.sac  on  this  group 
has  been  published  ;  but,  as  it  is  out  of  the  reach  of  ordinary  naturalists,  we 
do  not  possess  it,  and  therefore  cannot  consult  it.  This  is  one  out  of  the 
numerous  evils  of  these  ouvrages  de  luxe. 


250  SHELLS    AND    SHELL-FISH.  PART  I. 

by  the  fishermen.  The  head  and  lips  are  much  like  those 
of  a  slug ;  and  the  lower  tentaeula,  which  are  flattened, 
are  small,  and  placed  on  the  edge  of  the  lower  lip_, 
while  the  eyes  are  situated  above  them  ;  the  branchia 
are  composed  of  complicated  lamellae,  placed  on  the 
back,  but  covered  by  a  small  membraneous  mantle,  in 
which  is  a  thin,  convex,  and  horny  plate,  hardly  to  be 
called  a  shell,  since  it  more  resembles  an  operculum. 
The  edges  of  the  foot,  which  is  enormous,  forms  around 
it  a  prominent  margin  or  crest,  so  dilated  that  they  can 
be  thrown  over  the  back,  just  like  the  mantle  of  the 
cowries  and  the  Bullce ;  and  with  these  processes  the 
animal  occasionally  swims.  "  An  enormous  mem- 
braneous crop,"  observes  Cuvier,  "  leads  to  a  muscular 
gizzard,  armed  internally  with  cartilaginous  and  pyra- 
midical  processes,  which  is  followed  by  a  third  stomach, 
provided  with  sharp  hooks  ;  and  this  again  by  a  fourth, 
in  the  form  of  a  ccecum."  These  animals  appear  to 
feed  only  on  sea-weed,  and  are  oviparous.  Such  are 
the  characters  of  the  typical  Aplysiance,  but  there  are 
several  exceptions.  In  the  genus  Aplysia  Linn.,  the 
body  is  excessively  thick,  and  the  lobes  so  large  that 
they  can  be  used  for  swimming :  but  in  T/iallepus* 
Sw.,  the  form  is  much  more  slender,  the  lobes  shorter, 
"  the  eyes  not  visible,"  and  the  lower  pair  of  tentacula 
wanting.  Dolabella,  according  to  the  published  figures, 
is  pear-shaped  ;  the  broadest  part,  which  is  rounded, 
being  posterior,  where  there  is  an  oblique  disk,  and  a 
hatchet-shaped  shell  which  covers  the  branchia.  The 
next  genus,  Bursatella,  is  still  shorter,  so  as  to  become 
nearly  globular  ;  and  the  edges  of  the  mantle  are  united 
over  the  back,  so  that  there  is  merely  a  passage  for  the 
water  to  pass  to  the  gills.     The  fifth  genus,  Notarchus, 

*  Thalleptis  ornatus  Sw.  A  most  beautiful  figure  of  a  species  to  which 
I  give  this  name,  is  among  Guilding's  drawings,  but  without  any  descrip- 
tion ;  it  was  evidently  finished  from  the  living  animal.  Thegeneral  colour 
is  sea  green,  covered  with  minute  black  and  white  dots  ;  the  edges  or  crests 
of  the  reflected  mantle  have  a  brosd  edging  of  the  richest  orange,  bordered 
on  their  outer  edge  with  a  line  of  deep  black  ;  the  tentacida  are  also 
orange,  and  formed  like  those  of  Ap/t/si'a.  Total  length  about  Sh  in.  The 
only  memorandum  on  the  drawing  is,  "  eyes  not  visible :"  whether  this  had 
any  covering  over  the  branchia  I  have  no  means  of  judging. 


CHAP.   IX. 


APLYSIA. BULLA. 


251 


closely  resembles  the  last  in  its  mantle,  but  is  remark- 
able for  the  body  being  beset  with  large,  flat,  irregular- 
shaped  and  palmated  membranes,  as  if  it  was  overgrown 
by  sea  weeds  ;  the  tentacula  are  only  two,  and  these 
also  are  covered  with  similar  processes  as  long  as  them- 
selves ;  there  is  no  shell ;  and  the  mouth,  resembling  a 
small  longitudinal  slit,  is  placed  beneath.*  We  have, 
no  doubt  that  all  these,  hereafter,  will  be  found  to  con- 
tain sub-genera,  some  of  which  we  may  subsequently 
characterise. 

(235.)   In  regard  to  the  Bulling,  we  have  already 

stated  our  difficulties,  as  they 
now  stand  in  Lamarck's  and 
Cuvier's  arrangements.  Some 
have  external,  some  internal, 
shells,  thin  or  strong,  horny  or 
calcareous,  coloured  or  hyaline ; 
in  all  these,  however,  the  ovi- 
form or  bulla-shape  is  uniformly 
preserved.  The  annexed  cut 
from  Guilding's  drawings  of  a 
species  allied  to  B.  aperta,  will 
show  how  nearly  the  animal  is 
related  to  the  AplysiancB,  while 
it  gives  a  correct  idea  of  the 
general  character  of  such  types 
as  have  their  shell  concealed. 
In  the  genus  Doridium  f  of  Mecken,  the  shell  almost 
disappears  ;  according  to  M.  Rang  ^ ,  the  two  lateral  lobes 
of  the  animal  are  so  much  developed  that  they  can  be 
used  as  fins.  Many  of  the  BiiUinee  have  the  gizzard 
composed  of  bonv  pieces ;  the  tentacula  assume  the  ap- 
pearance of  large,  fleshy,  angulated  processes,  under 
which  are  very  minute  sessile  eyes. 

*  See  Riippell's  admirable  figure  of  jVo/arcAM5Mc/w/c/ws,  Atlas,  i.  pi.  7. 
fig.  2. 

f  Akera  Cuv. 

t  Manuel  de  L' Hist.  Nat.  des  MoHusques,  p.  146.  The  reader  will  find 
a  great  deal  of  original  and  valuable  information  in  this  unpretending  but 
excellent  little  volume. 


252  SHELLS    AND    SHELL-FISH.  PART  I. 

{9,36.)  The  two  next  types  are  Gasteropteron  and 
Pleiirohranclms.  The  first  is  a  most  interesting  form, 
since  it  connects  the  tribe  with  the  Cephalopoda.  Cu- 
vier,  however,  with  his  usual  infelicity  (wherever  na- 
tural affinities  are  concerned),  simply  remarks,  that  it 
"  appears  to  be  an  Akera,  the  margin  of  whose  foot  is 
developed  into  broad  wings  for  swimming,  which  it  per- 
forms on  its  back.  It  has  no  shell  or  stony  armature  to 
the  stomach ;  a  slight  fold  of  the  skin  is  the  only  ves- 
tige of  a  branchial  operculum  that  is  visible."  *  A  much 
better  account,  however,  is  given  by  M.  Rang  f,  who  ob- 
serves, that  this  ''  highly  interesting  "  animal  was  first 
made  known  by  M.  Delia  Chiaje,  the  learned  anatomist 
of  Naples,  who  considers  it  so  clearly  a  Fteropoda,  that 
he  has  named  it  Clio  Amati. 

(237-)  The  last  genus,  or  rather  sub-family,  is  the 
PLEUROBRANCHiNiE,  distinguished  from  all  others  by 
their  broad,  flattened,  and  oval  bodies  ;  but  especially  by 
the  feather-like  structure  of  their  gills,  which  are  placed 
on  the  right  side  of  the  body,  j  ust  under  the  edge  of  the 
mantle.  Here,  again,  we  recognise  the  cheloniform  type 
so  frequently  developed  among  the  Testacea,  and  of  which 
Chelisoma,  Chelinotus,  Parmophorus,  Chiton,  &c.  are 
such  striking  examples.  The  bodies  of  aU  the  animals 
now  before  us  are  shaped  like  those  of  tortoises ;  and  in 
some,  as  Pleurohranchus  Cuv.,  this  resemblance  is  car- 
ried so  far,  that  the  foot  represents  the  under  plate  of 
those  reptiles  ;  so  that,  to  use  the  words  of  Cuvier,  "  the 
body  is  equally  overlapped  by  the  mantle  and  by  the 
foot,  as  if  it  were  between  two  shields."  The  mantle, 
in  some  genera,  contains  a  calcareous  plate,  which  in 
Lamarck's  Umbrella  is  so  very  large  and  strong  as  to 
resemble  a  limpet,  but  is  immediately  known  by  the 
sharp  edge  of  its  circumference.  The  idea  that  this  shell 
could  by  any  possibility  have  ever  been  nntundlii  attached 
to  Xhe  foot  of  the  animal  (whence  the  name  Gastroplax), 
is  too  preposterous  to  require  further  notice.     Vie  here 

♦  Griff.  Cuv.  xii.  46.  f  Rang,  Manuel,  p.  148. 


CHAP.   X,  BIVALVE    SHELL-FISH    GENERALLY.  253 

close  our  survey  of  the  TectihrancMa,  and  with  it  the 
whole  of  the  pre-eminently  typical  Testacea.  The 
little  space  now  left_,  will  therefore  be  devoted  to  the  sub- 
typical  order. 


CHAP.  X. 


ON  THE  ORDER  DITHYRA,   OR  BIVALVE  SHELLS.  THE  AFFINITIES 

AND  ANALOGIES   OF  THE   UNIONID^,   OR   RIVER   UNIOS. 

(238.)  Our  survey  of  the  gastropod  shell-fish  has  so 
much  exceeded  the  limits  we  originally  intended,  that 
we  can  do  little  more  than  bestow  a  hasty  glance  en  the 
remaining  Testacea.  Comparatively  so  few  of  the  forms 
among  the  Gasteropoda  had  been  defined  by  our  pre- 
decessors, that  it  was  absolutely  necessary  to  treat  that 
order  in  much  detail :  but  this  is  not  t'le  case  with  the 
DiTHYRA ;  nearly  the  whole  of  the  genera  and  sub-genera 
have  been  defined;  with  the  single  exception  of  thellNio- 
NiD^,  to  the  illustration  of  which  we  have  consequently 
devoted  the  greatest  part  of  this  chapter.  A  few  remarks 
on  the  remaining  families,  with  an  exposition  of  their 
analogies,  is  all  that  our  space  will  admit.  We  could, 
indeed,  have  easily  made  this  single  order  alone  the  sub- 
ject of  another  volume;  but  as  nearly  all  the  genera  may 
be  said  to  be  established,  and  their  technical  distinctions 
are  given  in  the  systematic  arrangement,  the  reader  must 
be  satisfied  with  the  results  rather  than  with  the  detaih 
of  our  analysis. 

(239.)  The  DiTHYRA  *,  or  bivalve  shell-fish,  are  ani- 
mals whose  general  structure  resembles  that  of  the  oyster. 
They  are  without  any  distinct  head,  and  are  inclosed  in 
two  shelly  valves,  which,  by  means  of  certain  muscles 

*  Comprising  the  first  order  of  Cuvier's  Acephala,  the  seventh  order  of 
his  Gasteropoda,  and  the  fifth  class  of  his  MoUusca. 


254  SHELLS    AND    SHELL-FISH.  PART  1. 

running  through  the  body,  and  of  a  cartilaginous  hga- 
ment,  can  be  opened  and  shut  like  the  covers  of  a  book. 
Upon  opening  these,  the  mantle  is  seen  to  form  a  thin 
covering  over  all  the  interior  surface  of  the  shell ;  upon 
this  being  raised,  four  thin  lobes,  much  smaller,  will  be 
discerned,  called  by  Cuvier  the  "  branchial  leaflets ;" 
these,  again,  envelope  the  internal  parts,  as  the  heart, 
foot,  &c.  "  On  the  sides  of  the  mouth  are  four  trian- 
gular leaflets,"  which,  according  to  Cuvier,  ''  are  the 
extremities  of  the  two  lips,  and  serve  as  tentacula  ;"  the 
foot  is  a  mere  fleshy  mass,  and  is  moved  about  '^'^by  a  me- 
chanism analogous  to  that  of  the  tongue  in  quadrupeds." 
The  animal  is  attached  to  its  shell  either  by  a  strong  cen- 
tral muscle,  as  in  the  oyster;  or  by  two  transverse  ones, 
which  cross  from  one  to  the  other  valve,  and  leave  round- 
ish indentations,  generally  called  muscular  impressions. 
These  muscles,  however,  are  of  secondary  importance, 
when  compared  to  the  remarkable  modifications  of  the 
animal.  In  the  most  typical  Ditliijra,  form.ing  our 
Macrotrachia,  the  mantle  is  so  united  and  prolonged 
as  to  form  one  or  two  long  siphons  or  tubes  by  which  the 
food  is  imbibed;  while  in  the  next  tribe,  Atrachia, these 
siphons  are  entirely  wanting.  The  latter  animals  are 
also  distinguished  by  a  considerable  number  of  the  genera 
having  the  power  of  forming  a  bunch  of  cartilaginous 
threads  called  a  hyssus,  which  they  protrude  from  a  small 
opening  between  the  valves,  for  the  purpose  of  affixing 
themselves  to  marine  substances  :  the  whole  are  herma- 
phrodites. Such  are  the  two  chief  or  typical  tribes  of 
the  Dithyra.  The  three  which  are  aberrant,  lose  several 
of  these  characters,  and  possess  others.  In  the  Tubuli- 
branchia,  which  connect  the  Dithyra  and  the  Gastero- 
poda, the  structure  of  the  animal  is  a  singular  compound 
of  both  tribes ;  while  its  tubular  shell  reminds  us  of  a 
Teredo  fixed  on  other  substances  externally  instead  of 
internally.  The  Cheliosomid^,  instead  of  a  testaceous, 
has  a  coriaceous  covering,  analogous  to  the  chitons  and 
the  tortoises;  while  the  Branciiiopoda,  although  bivalve 
shells,  are  attached  by  a  fleshy  peduncle  or  a  strong  liga- 


CHAP.  X. 


DITHYRA. 


ANALOGIES. 


255 


ment,  which  passes  through  the  apex  or  summit  of  one 
of  the  valves  :  ^'  hke  the  other  bivalves/'  as  Cuvier  ob- 
serves, "  they  have  a  bilobed  mantle,  which,"  as  in  the 
oysters,  "  is  always  open  :  instead  of  feet,  they  have  two 
fleshy  arms,  furnished  with  numerous  filaments,  which 
are  protruded  or  withdrawn  at  pleasure."  Nearly  all  of 
them  possess  (like  their  prototypes,  the  Cephalopoda  and 
the  Tectibranchia)  an  internal  bony  support,  which  in 
these  consists  of  a  sort  of  framework  closely  resembling 
an  internal  skeleton,  and  rather  complicated.  Although 
innumerable  fossil  shells  of  the  Branchiopoda  abound  in 
the  older  formations,  very  few  occur  in  a  recent  state. 
Our  arrangement  of  the  entire  order  will  thus  be  in  the 
following  tribes:  —  1.  The Macrotrachia,  where  there 
are  either  one  or  two  siphons  ;  2.  The  Atrachia,  hav- 
ing none ;  S.  The  Tubulibranchia,  or  tubular  shell- 
fish, having  an  indistinct  head,  and  an  operculum  to 
their  shell ;  4.  The  Cheliosomid^,  with  a  cartilaginous 
covering  and  two  orifices;  and,  5.  The  Branchiopoda, 
or  anomian  bivalves.  The  whole  of  these,  it  will  now 
appear,  have  their  prototypes  in  the  Gasteropoda, 

Analogies  of  the  Orders  Dithyra  and  the  Gasteropoda. 


Tribes  of  the 
Bithyra. 

Macrotrachia. 

Atrachia. 
Branchiopoua. 

Cheliosomid^. 
Tubulibranchia. 


Analogies, 

r  Animal  with  the  mantle  formed'^ 
\  into  an  elongated  siphon,  sim-  > 
C     pie  or  double.  J 

Mantle  free,  and  without  a  siphon. 
C  Reciprocally  representing  the  Ce- 1 
X     pkalopoda.  J 

rBody  cheloniform,  oval,  covered'^ 
■<  with  testaceous  or  coriaceous  > 
C.     plates.  3 

Animal  of  the  gastropod  .struc- 
ture, furnished  with  an  obtuse 
head. 


Tribes  of  the 
Gasteropoda.     ] 

zoophaga. 

Phytophaga. 
Tectibranchia. 

Cyclobranchia. 
Scutibranchia. 


This  table  is  important,  were  it  only  to  prove  that 
the  usual  divisions  of  the  more  typical  bivalves  accord- 
ing to  the  number  of  their  muscles,  whether  one  or 
two,  is  not  a  natural  arrangement ;  because  it  destroys 


256 


SHELLS    AND    SHELL-FISH.  PART  I. 


the  beautiful  analogy  which  is  found  to  exist  in  the 
two  typical  tribes  of  the  Dithyra  and  the  Gasteropoda, 
and  is  not  borne  out  by  the  details  of  their  analysis. 

(240.)  The  Macrotrachia  and  the  Atrachia  com- 
prise by  far  the  greater  number,  and  the  most  perfect, 
of  all  the  bivalves  :  and  that  they  each  form  a  circular 
group,  will  be  apparent  from  the  following  consider- 
ations. The  Macrotrachia  may  be  said  to  have  their 
first  developement  in  the  family  oi  PhoUdcp, —  several 
of  which,  as  Teredo,  Clavagella,  &c,,  assume  the  form 
of  the  Tahulihranchia.  By  means  of  Pholas  and  its 
sub-genera,  there  is  a  direct  passage  to  the  Myad^ 
through  Solen  :  these  semitubular  shells  are  succeeded 
by  Mya  and  Mactra,  where  all  appearance  of  the 
gaping  peculiarity  of  the  Myadce  ceases.  Vi,^e  enter 
the  Tellinidce  by  means  of  the  river  genera  allied  to 
Cyclas;  and  thus,  through  Venus,  reach  the  TeJMncp, 
where  the  two  siphons  of  the  animal  are  of  enormous 
length.  Cardissa  Sw.  and  Pleurorynchus  of  Phillips 
open  the  passage  to  the  Chamid^,  where  we  see  the 
siphons  much  reduced,  and  almost  obsolete  in  Hippopus 
and  Tridacna.  The  aberrant  genera  of  Cardita  and 
Chama  unite  with  Cypricardia,  and  lead  to  the  perfo- 
rating family  of  the  Saxicavid^,  into  which  also 
enter  Petricola,  Saxicava,  Coralophaga,  and  Thracia. 
Finally,  all  these  are  as  evidently  connected  to  Gale- 
omma,  as  Galeomma  is  to  Gastrochina.  Thus  we 
again  arrive  among  the  Pholadcp,  and  the  circle  of 
the  Macrotrachia  is  closed. 

(241.)  The  course  of  the  Atrachia  is  precisely 
similar.  Cuvier  has  already  pointed  out  the  connection 
of  the  ChamidcE  to  the  Unionidcp;  while  the  genus 
Iridina  in  the  latter,  and  Nucula  in  the  Arcadje,  show 
that  the  two  families  follow  each  other.  The  passage 
from  these  to  the  AvicuLin^  is  still  more  perfect,upon 
looking  to  the  genera  Byssourca  and  Mod'wla:  then 
follow  Crenatula,  Malleus,  Avicula,  and  Pinna,  which, 
uniting  to  Modlolii,  completes  this  group.  Avicula 
opens  the  passag?  to  the  Ostreid.*;,  which  are  entered 


CHAP.   X.  MACROTRACHIA  AND  ATRACHIA.  257 

by  means  of  Lima  and  Pecten.  Finally,  in  order  to 
close  this  circle,  we  have  the  Etherid^,  which,  with 
Mulleria,  "  is  remarkable  as  a  group  possessing  in 
itself  both  the  character  of  being  intermediate  between 
Etheria  and  Ostrea,  and  as  apparently  connecting  the 
regular  freshwater  bivalves  with  the  regular  marine 
bivalves,  as  Ostrea.*  The  sinus  at  the  posterior  ex- 
tremity of  the  hgament  of  3fuUeria  resembles  the 
Unionidce  and  the  Etheria;  while  in  its  single  mus- 
cular impression,  as  well  as  its  general  form,  it  ap- 
proaches to  Ostrea."  This  obvious  affinity  at  once 
closes  the  circle  of  the  Atrachia,  by  the  series  re- 
turning to  the  Unionidcp.  The  following  table  will 
consequently  exhibit  the  mutual  relations  of  both  these 
tribes: — 

Analogies  of  the  Macrotrachia  and  the  Atrachia. 

Families  of  the  A„r,JnaiPi  Families  of  the 

Macrotrachice.  Analogies.  Atrachia. 

rrr^.^.^r.r.^  fShells  veiv  compact,  the  valves  7  . 

Tellimd/e.  ^     ^1^3^^    0-         F     >  j        Arcaid^e. 

Mtad^.  Valves  gaping  at  one  extremity.  Aviculid^. 

TJ„^r.T>™,  C  Animals  affixed  to,  or  living  with- >         ^ 

Pholid^.  ]      in,  other  substances.  j         Ostreid^. 

SAXiCAViDiE.  Shells  irregular,  without  teeth.  Etherid^. 

^  r  Lateral  teeth  long,  linear,  only  on  7         r^ 

Chamid^.  J     one  side  of  the  bosses.  j         I^nionid^. 

(242.)  It  will  be  seen,  by  the  subsequent  arrangement 
of  the  genera,  that  they  follow  each  other  precisely  in  the 
same  way,  so  as  to  represent  the  families.  To  follow 
out  this  exposition,  however,  in  the  present  tribe,  as 
we  have  already  done  in  that  of  the  Gasteropoda,  is 
manifestly  impossible  ;  but,  as  we  state  this  fact  as  the 
result  of  a  careful  analysis  of  the  whole,  the  reader, 
knowing  the  general  principle,  may  apply  it  to  any 
particular  group,  whose  analogies  he  wishes  to  trace. 
As  we  shall  enter  into  a  full  investigation  of  the  Unio- 
nidce,  or  river  pearl-shells,   our   remaining   space   will 

*  Sowerby's  Genera  of  Shells,  art.  Mulleria. 


258  SHELLS    AND    SHELL-FISH.  PART  I. 

barely  be  sufficient  for  a  few  general  remarks  on  the 
other  families  ;  and  these  will  be  confined  to  the  forms 
most  characteristic  of  the  primary  types  of  bivalves. 

(243.)  The  Tuhulihranchia,  or  tubular  tribe,  may 
be  traced  in  almost  every  one  of  the  above  families  : 
it  is  shown  by  an  unusual  elongation  of  the  shell,  which 
is  at  the  same  time  very  narrow,  a  ad  inclined  to  be 
cylindrical.  The  whole  of  the  Solens  have  this 
analogy,  as  well  as  the  genus  Anatina,  in  the  Myadce. 
Psammobia  and  Donax  are  modifications  of  the  same  ; 
and  so  also  is  Cardissa:  most  of  these  also  have  the 
anterior  side  remarkably  short,  precisely  as  in  all  the 
PholadcE.  Coralophaga  is  another  example ;  and  it  is 
even  apparent  in  one  of  the  sub-genera  of  Cardium. 
This  type  of  form  is  equally,  and  even  more  strongly, 
developed  in  the  order  Atbachia  :  thus,  we  detect  it  in 
Jridina,  Byssoarca,  Lithophaga,  and  Avicula;  all  of" 
which  are  the  most  elongated  in  general  shape,  and  the 
most  abbreviated  at  their  anterior  extremity.  In  an- 
other type,  which  evidently  runs  through  the  whole,  it 
is  characterised  either  by  the  absence  of  all  teeth  to  the 
valves,  or  by  there  being  but  two,  placed  in  the  centre, 
and  resembling  the  letter  V  reversed.  This  is  almost 
always  found  in  that  division  of  a  group  which  is  most 
aberrant  in  its  own  circle,  as  the  Saxicavidce  and  the 
EtheridcB;  the  Anodontince  among  the  river  bivalves  ; 
as  well  as  the  genera  Pholadomya,  Thracia,  Acardo, 
Loripes,  Pinna,  Placuna,  Plicatula,  Trigonia,  Pan- 
dora, &c.  A  third  type  of  form  is  evidently  intended 
to  represent  the  Branchiopoda  ;  its  chief  distinction 
being  that  of  having  an  internal  cartilage — not,  indeed, 
protruding  through  an  opening  in  the  valves,  but 
situated  between  the  cardinal  teeth.  This  is  well 
known  to  be  the  predominant  characteristic  of  all  the 
MactridcE,  and  of  their  prototypes  scattered  in  other 
groups,  as  Gnafhodon,  Erycina,  Niicula,  UnguUna , 
Pecten,  Pedum,  &c.  Now,  it  is  a  remarkable  fact,  that, 
on  comparing  our  analysis  of  the  whole  of  these  circular 
groups,    we  almost   invariably  found   that  these   three 


CHAP.  X.  UNIONIDJS,  GENERALLY.  259 

types  always  followed  each  other^  and  that  they  consti- 
tuted the  aberrant  divisions.  On  looking  to  the  typical 
and  the  sub-typical  divisions  of  the  larger  groups,  we 
find  that  the  first  are  the  most  perfectly  closed  bivalves, 
or  the  most  highly  finished  and  ornamented  ;  while  the 
latter  seem  not  to  have  so  much  the  power  of  free 
motion,  and  usually  gape  a  Uttle  at  one  extremity,  —  a 
sure  sign  that  their  inhabitants  live  in  the  ground,  and 
do  not  roam  from  place  to  place.  In  the  tribe  oiMacro- 
trachia,  we  thus  have  the  pre-eminent  type  in  the 
Tellinidce,  and  the  sub-typical  in  the  MyadcE ;  the 
former  being  represented  again  by  the  Arcidce;  and  the 
latter  by  the  Aviculidce.  We  must,  however,  quit  this 
inviting  train  of  generalisations,  and  proceed  at  once 
to  the  only  family  of  the  Dithyra  which  stands  in  need 
of  a  more  detailed  examination. 

(244.)  The  Unionidje,  as  before  observed,  are  en- 
tirely fluviatile,  and  are  the  only  river  shell-fish  in 
this  tribe;  except  indeed  the  Etherirnr,  by  which  they  are 
connected  to  the  marine  oysters.  As  they  form  that 
particular  family  which  unites  the  Atrachia  to  the 
Macrotrachia,  we  naturally  supposed,  that  when  they 
were  better  known,  some  trace  of  the  siphons  so  cha- 
racteristic of  the  latter  tribe  would  be  found  in  one  of 
the  aberrant  groups  ;  and  in  this  expectation  we  have 
not  been  disappointed.  M.  Deshayes,  it  appears,  has 
announced  the  fact,  that  the  animal  of  Iridina  pos- 
sesses these  tubes ;  and  it  further  appears  that  the  major 
part  of  the  family,  although  really  without  these  organs 
in  a  permanent  state,  have  yet  the  power  of  forming 
two  temporary  tubes,  with  the  posterior  edge  of  the 
mantle,  which  is  fringed  with  cilia,  serving  to  deter- 
mine the  direction  of  the  water  which  flows  into  the 
branchia.*  Thus,  whether  we  regard  the  shell  or  its 
animal,  we  find  that  the  natural  station  of  the  Unionida' 
is  determined  by  nature  ;  they  are  the  last  of  the  Atra- 
chia  as  the  ChamidcB  are  the  first  of  the  Macrotrachia. 


*  Lea's  Synopsis,  p.  5. 

s  2 


260  SHELLS    AND    SHELL-FISH.  PART  1, 

(245.)  As  the  whole  of  these  shell-fish  are  inhabit- 
ants of  fresh  waters,  and  chiefly  of  rivers,  so  are  they 
most  abundant  in  those  countries  whose  lofty  mountains 
supply  copious  and  never-failing  supplies  of  their  fa- 
vourite element.    The  mighty  rivers  of  the  New  "World 
are    no  less  remarkable    for    their    innumerable    rami- 
fications, than  for  the  almost  endless  number  of  these 
shell-fish   which   live    in    them.     The  American    spe- 
cies,   in  fact,  comprise  more  than  seven  tenths  of  the 
whole  number  yet  made  known  ;  five  or  six  are  alone 
found    in   Europe ;    about    the     same    number    occur 
in  Australia,  a  few  more  in  Asia,  and  we  have   as  yet 
seen   none  from  Africa.     Why  the  immense  rivers  of 
the  East  should  be  so  destitute  of  Unionidcp,  is  a  ques- 
tion we  know  not  how  to  solve.     One  reason  may  pro- 
bably be,  that  they  have  not  been  sufficiently  examined. 
Before   the  researches  of  Spix  and  Martins  in   Brazil, 
scarcely  five  were  known  from  South  America,  —  so  that 
nearly  all  that  they  found  were  new,  and  others  will  no 
doubt  be  soon  brought  to  light.      It  is  difficult,  indeed, 
to  assign  any  reason  why  the  tropical  rivers  of  the  New 
World   should  not  produce  these  shell- fish  at  least  as 
plentifully  as  the  more  temperate  waters,  such  as  the 
Ohio  and  its  tributary  streams.     The  UnionidxB  almost 
always  have  their  bosses  more   or  less  rubbed  and  in- 
jured,  occasioned  by  the  friction  of  stones  and  other 
substances   carried  onward  by   the  stream.     Although 
generally  of  an  olive  brown  colour,  occasionally  varied  with 
obscure  rays  on  their  outer  surface,  the  interior  of  these 
shells  are    often  particularly  brilliant,  and    their  sub- 
stance is  always  perlaceous.  Hence  they  are  now  manu- 
factured in  America  into  pearl  buttons  and  other  orna- 
ments.  Ileal  pearls,  also,  are  occasionally  found  in  some 
of  the  species.      We  once  took  from  a  small  specimen  of 
U.  circulus,  a  beautiful  little  pearl,  half  the  size  of  a  small 
pea,  which  is  now  in  the  possession  of  our  friend  Mrs. 
Corrie  of  Birmingham.      The  Mya  margurUifera  Linn., 
still  found   in  some  of  our  own  rivers,  produced  those 
pearls  for  which  Britain  was  so  famous  in  the  time  of  the 


CHAP.  X.  UNIOXID^,   PRIMARY  CIRCLE.  26 1 

Romans.  Some  of  the  American  species  are  remarkably 
thick^  particularly  at  their  bosses,  which^  in  proportion  as 
they  are  rubbed,  the  animal  thickens  internally;  and  this 
is  very  remarkable  in  old  shells.  In  regard  to  the  ana- 
tomy of  the  animals,  we  must  refer  the  reader  to  Poll's 
account  of  the  European  species,  and  to  the  scattered 
notices  of  the  American  in  various  other  publications. 

(246.)  The  natural  arrangement  of  this  family,  or 
rather  the  principle  of  its  variation,  in  regard  to  the  shell, 
is  precisely  the  same  as  in  all  the  other  groups  of  the 
DiTHYRA.  The  most  typical  groups  are  those  two 
which  stand  between  the  elongated  and  the  cuneated 
types ;  the  most  aberrant  being  intermediate  with  the 
two  latter,  and  having  no  teeth.  The  typical  groups, 
consequently,  possess  the  two  sorts  of  teeth^  cardinal  and 
lateral,  in  the  highest  perfection  ;  while,  in  the  three 
aberrant  divisions,  only  one  of  these  sorts  is  apparent, 
or  none.  As  a  whole,  this  is  the  most  perfect  family, 
perhaps,  of  the  bivalve  Testacea.  Like  the  Psittacid<E 
and  the  Picidce  among  scansorial  birds,  the  shells  of  the 
Unionidce  have  such  a  stamp  of  identity  upon  them, 
that  they  cannot  possibly  be  confounded  with  those  of 
any  other  family  ;  while  their  amazing  diversity,  on  the 
other  hand,  offers  the  very  best  facilities  for  determining 
the  natural  succession  of  their  forms.  Under  the  beUef 
that  this  would  long  ago  have  been  done  by  those  Ame- 
rican conchologists  who  have  especially  studied  this 
portion  of  their  native  fauna,  we  suspended  our  labours 
towards  this  object  some  years  ago  ;  but  as  nothing  has 
yet  been  done  to  supercede  our  own  views,  they  will 
here  be  detailed  with  as  much  brevity  as  the  subject 
will  admit. 

(247.)  Presuming  that  the  station  of  the  Unionid<B, 
as  a  family,  has  been  determined ;  and  that  Tridin.ce, 
from  possessing  true  siphons,  is  that  aberrant  group 
which  comes  nearest  to  the  Chamadce  in  the  tribe  of 
Macrotrachia,  we  thus  get  a  sure  point  from  which  to 
start :  our  first  object  is  to  show  that  the  whole  family 
form  a  circular  group,  with  no  chasm,  hiatus,  or  inter- 

s  3 


262  SHELLS    AND    SHELL-FISH.  PART  I. 

ruption  so  great  as  to  cast  a  doubt  on  the  truth  of  this 
proposition,  or  to  admit  the  introduction  of  any  shell- 
fish that  have  been  arranged  in  other  families.  On  this 
ground,  and  not  for  its  typical  perfection,  we  commence 
our  survey  with  Iridina,  where  the  transverse  or  tubuli- 
form  structure  of  shell  is  so  conspicuous  :  here  the 
cardinal  teeth  are  wanting,  being  absorbed  in  one  single 
lateral  tooth  which  occupies  the  whole  length  of  the 
hinge  margin ;  this  lateral  tooth  being  tuberculated  or 
crenated.  Now,  the  only  other  examples  where  the  car- 
dinal teeth  put  on  the  aspect  of  lateral  teeth,  and  are 
also  crenated,  is  in  such  shells  as  Hyria  avicularis  Lam., 
where,  in  fact,  the  cardinal  teeth  *  are  so  far  removed 
towards  the  side  as  to  assume  the  aspect  of  lateral  teeth  ; 
the  interval  between  those  on  the  other  side  of  the  shell 
being  occupied  by  a  few  irregular  crenations,  similar  to 
those,  in  short,  of  Iridina  :  on  coming  to  Hyria  corru- 
gata  Lam.,  these  crenations  disappear,  the  cardinal  teeth 
assume  their  true  position  immediately  under  the  bosses, 
and  the  passage  thus  becomes  opened  to  Lamarck's  Cas- 
talia.  The  Indian  Unio  corrugata  Lam.  then  succeeds, 
and  from  standing  at  the  confines  of  Hyria,  connects 
that  group,  in  conjunction  with  other  species  more  elon- 
gated, with  Mysca  ovata  of  Turton.  This  brings  us  at 
once  to  the  genus  Unio  of  Lamarck,  where  the  chain  of 
aflUnity  passes  on  from  Mysca  nasuta  Sw.  to  the  Unio 
ossidens.  The  pre-eminent  types  of  the  whole  then 
succeed,  as  shown  in  U.  cuneatus  and  the  Mytiloides  of 
Raf.  By  means  of  U.  JEsopus,  we  pass  to  Lamarck's 
sinuosa,  Unio  gioas  Sw.,  and  so  enter  Say's  Alasmodon 
by  the  well-known  Unio  margaritifera  of  Europe. 
From  this  point  even  the  cardinal  teeth  begin  to  dis- 
appear ;  for  A. undulatus  and  calceolus  bring  us  close  to, 
and  rugoftus  within,  the  confines  of  Anodon  :  all  that 
now  remains  of  the  teeth  is  a  slight  elevation  beneath 
the  hinge  margin,  as  in  Dipsus  Leach  ;  and  even  this 
finally  disappears,  as  in   the  typical  anodons.     Gradu- 

*  True  cardinal  teeth  are  placed  immediately  beneath  the  bosses,  and 
not  on  one  side,  as  in  Hyria  avicularis. 


CHAP.   X.  UNIONID^,   PRIMARY   CIRCLE.  26S 

ally,  however,  the  shell  becomes  stronger,  more  elon- 
gated, and  the  hinge  margin  again  thickened  :  this  is 
particularly  observable  in  a  species  from  the  Nile  *, 
placed  by  some  writers  as  an  anodon,  and  by  others  as 
an  Iridina  ;  but  to  which  it  really  belongs  is  not,  at 
present,  material.  Suffice  it,  that  thus  the  series  of  the 
Unionidoe  returns  into  itself,  and  forms  as  perfect  a 
circle  as  any,  perhaps,  contained  in  this  volume. 

(248.)  The  proportion  which  the  three  aberrant  di- 
visions bear  to  the  pre-eminently  typical,  is  nearly  the 
same  in  this  as  in  all  natural  groups  of  the  animal 
kingdom.  By  far  the  most  numerous  in  forms  and 
species  is  the  typical  genus  Unio,  which  contains,  in 
fact,  more  than  all  the  rest  put  together  ;  the  few^est, 
perhaps,  are  in  Hyria  and  Iridina  :  hence  it  naturally 
results,  that  the  interval  between  the  species,  in  these 
two  latter,  are  wider  than  in  the  former.  But  these  little 
intervals,  more  or  less,  occur  in  every  group  in  nature  ; 
and  provided  that  no  animals  are  found  in  other  groups, 
which  appear  to  fill  up  these  chasms,  we  may  be  quite 
sure  our  series  is  correct.  In  the  Unionidcp,  this  per- 
plexity can  never  happen  ;  their  general  structure  is  so 
peculiar,  that  no  intervals  among  them  can  be  filled  up 
by  shell-fish  of  other  groups :  hence  we  may  feel  per- 
fectly sure  that  the  break  in  the  line  of  continuity  ori- 
ginates either  from  a  few  links  having  not  yet  been 
discovered,  or  that  they  exist  only  in  a  fossil  state. 
The  proximity,  for  instance,  between  Iridina  and  Ano- 
don is  so  close,  that  there  is  not  the  slightest  link 
wanting ;  but  between  Iridina  and  Hyria  the  difference 
is  more  marked.  Are  we,  then,  to  conclude  from  this, 
that  these  two  are  not  also  connected  }  Certainly  not. 
We  know  that  Hyria  is  im.perceptibly  united  to  Unio, 
on  one  side  ;  and  if,  on  the  other,  it  approaches  nearer 
to  Iridina  than  does  any  other  genus,  we  have  induc- 
tive proof  that  they  follow  each  other,  although  one  or 
two  of  the  links  may  appear  wanting. 

•  This  may  possibly  be  the  A.  rubens  Lam. 

s  4 


264 


SHELLS    AND    SHELL-FISH. 


PART  I. 


(249.)  The  primary  divisions  of  this  family^  as  we 
stated  some  years  ago,  are  typically  represented  by  the 
following  genera:  —  Unio,  Hyria,  Iridina,  Anodon  of 
Lamarck,  and  Alasmodon  of  Say.*  Having  shown  that 
these  form  a  circular  group,  it  follows,  that  these  divi- 
sions are  sub-families,  to  which  we  give  the  usual  ter- 
mination in  ina.  Their  secondary  groups  are  conse- 
quently genera,  and  their  third  are  sub-genera.  We  shall 
now  take  a  rapid  survey  of  each  in  their  natural  order 
of  succession. 

(250.)  The  Unionin^  stand  at  the  head  of  the 
family  ;  and  their  typical  characters  may  be  thus  briefly 
stated  :  —  The  form  is  various,  but  the  two  cardinal 
teeth t  and  the  anterior  lateral  teeth  are  always  present; 
the  umbones,  or  bosses,  are  sometimes  wrinkled  longitu- 
dinally, but  never  sulcated  transversely,  —  this  latter 
character  being  peculiar  to  Hyria.  Thus  detached  by 
the  most  simple  and  definite  characters  furnished  by 
the  shell,  we  find  the  whole  of  the  species  will  arrange 
themselves  under  one  or  other  of  the  following  genera  : 
—  In  Unio  pre-eminently  so  called,  the  umbones,  or 
bosses,  are  very  large,  thick,  and  prominent;  and  the  car- 
dinal teeth  (^jig.  4?.  «) 
either  in  an  obliquely 
perpendicular  line  with 
the  base  of  the  shell,  or 
receding  in  a  contrary 
direction,  to  the  ante- 
rior margin.  The 
form  is  various ;  but 
the  hinge  margin,    al- 


*  Mr.  Lea,  in  his  valuable  paper  on  Unionidce  (Am.  Tr.),  observes  that  I 
have  stated"  difficulties  in  adopting  these  genera."  I  am  not  conscious  of 
ever  having  done  so,  and  have  taken  every  occasion  of  expressing  my  be- 
lief that  they  are  perfectly  natural.  As  I  entirely  dissent  from  the  views 
of  this  gentleman,  both  in  his  divisions,  in  his  genera,  and  even  in  many  of 
his  species,  I  am  anxious  not  to  be  misunderstood,  as  having  in  any  way 
changed  my  opinion  on  this  family.  Mr.  Lea  has,  however,  added  many 
interesting  and  beautiful  species,  for  which  hedeserves  the  thanks  of  everj 
naturalist ;  we  only  regret  that  all  his  arrangements  of  them  aj>pear  to  us  so 
very  artificial  and  perplexing. 

f  I  consider  these  teeth  as  two ;  not  as  one,  cl^t  into  two. 


CHAP.    X. 


SUB-FAMILY  OP  UNIONIxXJE. 


265 


though  sometimes  angulated,  in  the  most  aberrant  groups, 
is  never  connate ;  nor  is  the  shape  of  the  shell  properly 
cuneate.  In  the  next  genus,  Mglia  Sw.  {h),  the  car- 
dinal teeth  are  lengthened,  compressed,  and  take  a  di- 
rection precisely  opposite  to  the  above  ;  they  diverge, 
in  fact,  from  the  apex  towards  the  anterior  margin 
instead  of  from  it :  the  inner  tooth  is  smallest,  and  not, 
as  in  Unio,  the  largest.  The  shell  is  generally  cuneate 
and  the  bosses  prominent.  None  of  the  types  are  con- 
nate or  tuberculated.  In  Mysca  the  shells  are  more  or 
less  transversely  elongated,  much  thinner,  and  the  bosses 
much  smaller  than  in  the  two  preceding  genera;  and 
the  cardinal  teeth  differ  essentially  from  both  :  they  are 
much  compressed,  irregularly  crenated,  and  placed  as 
nearly  as  possible  on  a  parallel  line  with  the  anterior 
margin;  they  are  also  sometimes  so  thin  and   slightly 

divided,  that  they  ap- 
pear almost  blended  into 
one :  hence  they  are 
rarely  obtuse,  nor  is  the 
shell  winged  or  tubercu- 
lated. In  Lymnadia  alata 
{jig.  48.),  the  posterior 
part  of  the  hinge  margin 
is  greatly  elevated,  and 
the  shell  is  strictly  con- 
nate ;  while  in  Megado- 
mus,  of  which  our  M. 
gigas  is  the  type,  the  cardinal  teeth  are  like  those  of 
Unto,  but  there  is  only  one  lateral  tooth  in  each  valve. 

(251.)  To  these  gTOups  we  shall  presently  return  ; 
in  the  mean  time  it  will  be  as  well  in  this  place  to  show 
how  perfectly  they  represent  the  five  primary  divisions 
of  the  whole  family.  It  is  immaterial  to  our  present 
object,  whether  the  genus  Mysca  contains  a  portion  of 
those  shells  we  have  arranged  under  the  name  of  Poto- 
mida,  since  none  of  these  latter  can  be  looked  upon  as 
typical  examples  of  Mysca. 


266 


SHELLS    AND    SHELL-FISH. 


PART  I. 


Analogies  of  the  Genera  q/"  UNiONiNi«. 


Genera  of  the 
Unionince. 

Unto. 
Mglia. 

My  sea. 

Lymnadia. 
Megadomus. 


Analogical  Characters. 

Cardinal  teeth  thick,  short 
f  Cardinal  teeth  compressed, ) 
I  lengthened;  shell  cuneate.  J 
r Shell  lengthened;  cardinal  teeth') 
■J  crenated,  almost  on  a  linewith  > 
t     the  lateral  teeth.  "         j 

f Shell    thin,    winged;    umbones") 
(_     small.  3 

C  Lateral  teeth  imperfect,  one  or 
t     none. 


Types  of  the 

Sub-families  of  die 

Unionida. 

Unio. 
Hyria. 


] 


Iridina. 

Anodon. 
Alasmodox. 


These  analogies  are  very  remarkable,  particularly 
when  we  confine  our  attention  to  the  types  of  each  of  the 
groups  thus  brought  into  comparison.     Mglia  ovata  Sw. 

(Unio  ovatus  of  Say) 
(fig.4fQ.),  like  Hyria,  has 
the  cardinal  teeth  as- 
suming the  shape  and 
the  position  of  lateral 
teeth  ;  and  both  have 
merely  two  or  three  tu- 
bercles immediately  be- 
neath the  bosses.  The 
elongated  form  of  all  the  species  of  Mysca  reminds  us 
of  Iridina,  no  less  than  the  crenated  edge  and  mar- 
ginal direction  of  the  cardinal  teeth,  li  Lymnadia,  again, 
had  no  cardinal  teeth,  it  would  be  a  Dipsus  of  Leach  ; 
and  both  these  have  the  very  aspect  of  Anodon.  Mega- 
domus is  the  only  type  in  which  the  lateral  teeth  are 
imperfect ;  hence  a  truer  prototype  of  Alasmodon, 
where  both  those  teeth  are  entirely  wanting,  could 
scarcely  be  found ;  particularly  as  the  cardinal  teeth 
are  precisely  like  those  of  the  typical  genus  Unio.  Our 
limits,  and,  indeed,  our  materials  of  specific  nomen- 
clature *,  will  not  permit  us  to  analyse  the  whole   of 

♦  The  specific  descriptions  of  Lamarck  are  scarcely  less  unsatisfactory 
than  many  of  those  recently  published  in  America ;  I  have  seen  totally 


CHAP.   X. 


UNIONIN^^   ANALOGIES. 


267 


these  genera.  Two,  however,  where  the  natural  series 
appear  to  us  very  strikingly  marked,  will  be  now 
noticed  :  the  first  regards  the  sub-genera  of  our  genus 
Unio,  and  the  circular  succession  of  the  types  of  form 
in  two  of  them. 

(252.)  The  genus  Unio,  separated  by  its  cardinal 
teeth  from  tEglia,  as  already  shown  (JigAl-b),  contains 
five  distinct  types  of  form,  which,  from  the  multiplicity 
of  species,  and  for  the  greater  facility  of  nomenclature, 
we  shall  designate  under  the  following  sub-generic 
names: —  1.  Unio:  the  bosses  or  umbones  prominent 
and  tumid,  the  circumference  and  the  posterior  hinge  mar- 
gin never  angulated,  and  both  thecardinal  teeth  very  much 
receding  from  the  anterior  margin,  as  in  U.  Mytilo'ides 
Raf.,  and  all  such  species  or  varieties.  2.  Cunicula,  where 
the  umbones  are  even  larger,  but  not  tumid,  being,  as  it 
were,  compressed  or  flattened  :  the  shell  is  generally 
oval,  or  angulated  at  the  base  of  the  posterior  side ;  — 
examples,  C.  planulata,  cuneata,  purpurata,  Lam.,  &c. : 
the  outer  cardinal  tooth  slightly  diverges  from  the  base 

of  the  inner.  S.  Ligumia  :  the 
form  is  particularly  long,  like 
that  of  Iridina,  the  umbones 
small  and  retuse,  and  the  car- 
dinal teeth  close  to  the  ante- 
rior end  ;  as  in  U.  recta  Lam. 
4.  Theliderma :  the  form  is 
various,  but  the  posterior  hinge 
margin  is  generally  elevated 
and  angulated,  and  the  outside 
of  the  valves  tuberculated  or 
granulated,  —  a  character  not 


distinct  species  sent  from  that  country,  evidently  labelled  by  the  same  hand, 
yet  bearing  the  same  specific  name.  Mr.  Lea's  Synopsis  leaves  this  part 
of  the  subject  almost  as  obsure  as  ever,  because  he  merely  cites  the  name, 
without  giving  any  reference  to  the  works  of  the  authors  he  quotes.  By 
his  plan,  as  novel  as  it  is  detrimental  to  science  and  all  critical  inquiry, 
the  author  (no  doubt,  unintentionally)  imposes  an  effectual  bar  to  the  ve- 
rification of  his  own  nomenclature,  no  one  here  being  acquainted  with  all 
the  detached  papers  on  these  shells  printed  in  America. 


268 


SHELLS    AND    SHELL-FISH. 


PART  I. 


found  in  any  other  of  these  groups*  (T.  metanevra 
Ra.f.  Jig.  50.).  5.  Potomida :  the  shell  rather  short 
and  oval ;  the  umbones  prominent,  but  not  so  large  as 
in  Unio  ;  the  outer  surface  smooth  ;  the  cardinal  teeth 
thick,  perpendicular,  but  the  outer  one  diverging.  These 
are  mostly  European  shells,  and  are  represented  by  U.  si- 
niiata  Lam.,  and  our  P.  corrugata  {fig.  51.).  Between 

51  these  sub-genera  are  in- 
tervening species,  or 
rather  types  of  form, 
which  blend  the  whole 
into  a  continuous  chain 
of  affinity  ;  thus  P.  si- 
nuala  is  so  like  some  of 
the  typical  Unios,  that 
the  direction  of  the  outer 
cardinal  tooth  and  the  comparative  smallness  of  the  bosses 
alone  distinguish  them.  Leaving,  however,  these  inter- 
vening or  connectant  species,  and  looking  only  to  the 
types,  we  shall  see  by  the  following  table  that  they 
have  a  resemblance  to  the  primary  divisions  of  the 
whole  family,  and  to  the  genera  of  the  UnionincB. 


Sub-genera 
of 
Unio. 

Unio. 

Cunicula. 
Ligumea. 
Thelider7na. 

Potomida. 


Analogies  of  the  Sub-genera  of  Unio. 


Analogies. 


Sub-families 
of 
Unionidce. 


f  Shell  ovate;    cardinal  teeth  7  TTxr,^.„„^ 
I     not  diverging.  jUNiONmiE. 

f  Shell     more     oval,    wedge- 7  u,.„.„  ^ 
I    shaped,  and  angulated.        JH^RIN^. 

Shell  very  much  lengthened.    Iridin^. 
f  Posterior  hinge  margin  gene-  7  * 
I     rally  winged.  j  Anodonin^. 

r  General  form  oval,  oblong  ;  T 

<     cardinal  teeth  obtuse,  di- 5- Alasmodonin.e.  Megadomus. 

C     verging,  sometimes  erect.    J 


Genera 

of 

UnioninzB. 

Unio. 

^GLIA. 

Mysca. 
Lymnadia. 


The  analogy  of  the  last  three  groups  is  not  so  satis- 
factory as  the  others,  and  this  excites  a  suspicion  that 

*  Except  U.  cornuius  and  ^sopus.    U.  nodosa.  Wood's  Conch,  nl.  22.  fig. 
1,  2.,  seems  to  belong  to  this  group. 


CHAP.   X. 


SUBGENERA  OF  UNIO. 


^69 


our  Megadomus  fills  up  the  interval  between  such  spe- 
cies as  Lamarck's  Peruvianus  and  Msopus ;  but  this 
would  exclude  the  European  Unio  sinuata,  littoralis, 
Szc,  which  seem  closely  united  to  the  typical  or  Ame- 
rican group  by  their  short,  oval  shape,  and  the  thickness 
of  their  cardinal  teeth.     On  the  other  hand,  we  feel 

persuaded  ihat  our  Po- 
tomidcB  must  be  kept 
distinct  from  the  sub- 
genus Unio;  and  this 
will  be  apparent  to  every 
one  who  looks  to  the 
annexed  cut  of  the  car- 
dinal teeth  of  Unio  My- 
tilo'ides  (fig.  52.),  and 
those  of  Potomida  corrugata  (^fig  51.). 

{9,5S.)  Two  of  these  sub-genera,  being  more  than 
usually  perfect  in  their  types  of  form,  or,  in  other 
words,  in  the  diversity  of  their  species,  will  next  be 
glanced  at,  for  the  purpose  of  showing  there  is  but  one 
principle  of  variation  throughout  the  entire  family. 
We  shall  first  take  the  sub-genus  Unio  as  here  re- 
stricted. The  types  of  this  are  seen  in  those  inequi- 
lateral shells  which  have  been  sent  to  us  from  America, 
as  the  U.  Mytilo'ides  Raf.  and  the  undatus  of  Barnes. 
Next  follow  those  which  are  nearly  round  and  equilateral, 
such  as  U.  Torsus  Raf.  Our  U.  truncatus,  very  much 
elongated,  is  the  third  type  of  form.  The  fourth,  which 
represents  Thelider'ma, is  perhaps  the  cornutus  of  Barnes ; 
while  the  fifth,  which  unites  the  last  to  the  first  type, 
is  an  American  species,  formed  like  ohliqua  Lea,  but 
with  small  scattered  tubercles  down  the  middle.  *  This 
unites  with  JEsopus,  and  again  brings  us  back  to  the 
undatus.  Thus,  in  the  confines  of  a  single  sub-genus, 
are  types  of  ^glia,  in  U.  Torsus  ;  Iridina,  in  U.  trun- 
catus ;  Anodon,  (through  Theliderima),  in  U.  nodosa  ; 


*  I  pretend  not  to  enter  upon  specific  names,  for  nearly  all  those  which 
belong  to  species  unfigured  appear  to  me  one  mass  of  confusion. 


270 


SHELLS    AND    SHELL-FISH. 


PART  I. 


and  probably  of  Alasmodon,  in  the  species  mentioned 
above.  We  say  probably,  because,  as  there  is  no  es- 
pecial evidence  to  prove  the  fact,  we  only  infer  it  from 
this  shell  having  a  structure  intermediate  between  no- 
dosa and  JEsopus  ;  hence,  it  occupies  the  same  station 
in  its  own  circle,  as  Alasmodon  does  in  that  of  the 
whole  family. 

(254.)  So  astonishingly  variable,  however,  are  the 
shells  of  this  family,  that  we  may  even  carry  our  ana- 
lysis still  further  ;  and  by  following  the  series  of  spe- 
cies which  arrange  with  Unio  Mytilo'ides,  we  shall  detect 
the  same  analogies  as  are  apparent  in  the  last  inves- 
tigation. Thus,  some  of  the  species  or  varieties  of 
Mytilo'ides  (as  gibbosus)  are  almost  equilateral ;  others 
pass  into  Ellipsis  and  sulcatus  of  Lea,  thus  assuming  the 
long  shape  of  truncata  and  Iridina  ;  next  follows 
c/yrnutus,  as  a  prototype  of  nodosa  and  Theliderma  ; 
and  finally,  Msopus  brings  us  again  to  such  shells  as 
U.  obliqua,  and  the  inequilateral  varieties  of  Lea's  gib- 
bosus.  Beyond  this  point,  it  is  utterly  impossible  to 
push  analysis,  except  it  be  carried  into  the  principle 
by  which  the  varieties  of  each  species  are  regulated;  and 
this,  we  firmly  believe,  is  in  conformity  with  the  very 
same  laws.  We  have  seen,  in  fact,  four  varieties  of 
the  Mytilo'ides,  which  assume  four  out  of  these  primary 
forms.  Some  are  inequilateral  {Jig.  53.),  some  trigonal, 
others  are  oval,  and  another  oblong :  whether  there  is 
any  one  with  small  nodules  to  represent  cornutus  and 

its  prototypes,  we  know 
not,  but  we  have  no  doubt 
that  such  a  variety  will 
be  found.*  Mytilo'ides, 
therefore,  we  consider 
the     most      typical 


as 


species  of  the  whole  fa- 
mily, concentrating,  in 
its  own  variations,  pro- 


*  Since  writing  the  above,  we  have  seen  a  variety  of  My/j7o»rf«  perfectly 
answering  our  theoretical  description,  in  the  hands  of  Mr.  Stuchbury. 


CHAP.   X. 


UNIONINiE.  —  THELODERM  A. 


271 


totypes  of  all  the  natural  divisions^  large  or  small,  of  the 
Unionid^e. 

(255.)  The  other  sub-genus,  which  contains  sec- 
tional types,  is  Theliderma  ;  and  this  we  shall  now 
briefly  notice.  It  will  be  remembered  that  we  have 
placed  this  sub-genus  immediately  after  Ligumia,  the 
type  of  which  is  the  Unio  recta  of  Lamarck.  Nearly 
all  these  shells  have  their  posterior  margin  dilated 
and  angulated,  and  thus  represent  the  genus  Ano- 
don  of  Lam.  Although  the  species  are  remarkably  va- 
ried, they  are  all  known  by  the  external  surface  being 
covered  by  numerous  tubercles  of  different  shapes,  which 
stud  every  part  of  the  sheU.  Where  we  find  a  cha- 
racter, however  trivial  it  may  appear,  pervading  a  whole 
group,  we  may  be  perfectly  assured  that  it  is  a  natural 
character,  although  it  may  not  be  the  only  one. 

(256.)  Now,  let  the  conchologist  place  before  him 
the  following  shells  (fig.  54!.);  —  1.  Irrorata  {a);    2. 


Metanevra  (6);  3.  Cylmdrica  (c)  ;  4.  Pustulata* 
Sw.  (<Z);  and,  5.  Plicata  (e);  — and  he  will  then  have 
what  we  consider  the  sectional  types  of  Theliderma. 
It  is  obvious  that  the  two  first  have  the  greatest  resem- 
blance to  each  other ;  both  are  nearly  circular,  and  tu- 
berculated  ;  but  irrorata  is  not  winged,  like  metanevra. 
Now,  this  difference,  trivial  as  it  seems,  is  accompanied 

•  We  merely  use  this  name  provisionally,  until  we  know  that  by  which 
it  has  been  distinguished  in  America, 


272  SHELLS    AND    SHELL-FISH.  PART  I. 

by  a  peculiarity  in  the  construction  of  the  animals^  first 
ascertained,  we  believe,  by  Mr.  Lea.     Here,  then,  we 
have  two  obvious  modifications  of  semicircular  warted 
shells — the  one  winged,  the  other  not.     This  rounded 
shape,  however,  begins  to  be  lost  in  succeeding  species, 
and  we  are  thus  conducted  to  that  singular  shell  the 
Unto  cylindricus  of  Say  (c).     Notwithstanding  its  un- 
common length,  it  yet  preserves,  in  every  other  part  of 
its  outward  appearance,  such  a  close  affinity  to  metanevra 
(h),  that,  without  knowing  why^  a  conchologist  would 
at  once  place  them  together.       On  turning  to  2^iicata 
we  see  another  modification :  this  species  is  neither  semi- 
circular, like  metanevra,  nor  elongated,  like  cylindrica; 
it  is  broadly  oval;  and,  instead  of  being  tuberculated,  has 
merely  two  or  three  deep  oblique  furrows :  it  exhibits, 
in  short,  but  one  out  of  the  three  typical  characters, 
— namely,  the  winged  elevation  of  the  posterior  angle. 
We  believe  more  than  two  or  three  species  pass  under 
the  name  of  plicata.     In  one  of  these,  kindly  sent  us 
by  our  liberal  friend  Mr.  Cooper,  of  New  York,  and 
labelled  as  "  a  very  old  specimen,"  there  is  but  one 
lateral  tooth  on  the  right  valve,  instead  of  two ;  so  that 
this  species  or  variety  actually  puts  on  the  very  cha- 
racter of  our  Megadomus  gigas*,  and  renders  both  proto- 
types of  Alasmodon.     But  has  Nature  no  method  in  these 
remarkable  variations  }   Can  it  be  supposed  that  the  devi- 
ation of  species,  or  of  races  of  the  same  species,  are 
regulated  by  no  fixed  principles,  while  all  the  rest  of 
creation,  inconceivably  diversified,  has  been  created  on 
one  and  the  same  plan  ?     Every  analogy  of  reasoning, 
every    ascertained    fact,    is    against    the    supposition. 
Whence,  then,  does  the  species  before  us  put  on  the  very 
aspect  of  another  genus  ?   Simply  for  this  reason,  —  that 
plicata,  and  its  immediate  allies,  represent   the  genus 
Alasmodon,  and  that  Nature  adopts  this  mode  of  in- 
structing us  in  her  favourite  theory  of  representation. 
With    plicata   must   be    associated  our  Unio  rugosus, 

*  It  is  this  fact  which  so  strongly  loads  me  to  suspect  that  there  may  be 
some  error  in  our  location  oi  FotomUia. 


CHAP     X.  UNIONIX^. THELIDERMA.  273 

where  the  form  of  the  shell  is  nearly  semicircular,  so  that 
we  again  return  to  irrorata,  from  whence  we  first  set 
out.  Four  types  of  the  group  are  now  disposed  of,  but 
another  is  obviously  wanting  ;  because,  although  there 
are  representations  of  four  genera  of  the  UnionidcB,  we 
have  not  yet  noticed  the  prototype  of  Anodon.  Now, 
this  type  is  in  the  ^Manchester  Museum,  and  was  sent  to 
us,  many  years  ago,  by  our  friend  professor  Rafinesque, 
without  a  name.  By  the  annexed  figure  (rf),  the  con- 
chologist  wiU  perceive  that,  in  its  outward  appearance, 
no  one  would  suspect  it  was  really  different  froni  the 
Alasmodon  riigosa  of  Barnes  ;  yet,  on  opening  the  valves, 
we  find  the  perfect  cardinal  and  lateral  teeth  of  Theli- 
derma.  The  anodons  are  remarkable  for  the  smallness 
and  the  depression  of  their  summits ;  and  this  is  the 
only  shell  of  its  own  group  which  possesses  this  cha- 
racter, Avhile  its  form  is  exactly  intermediate  between 
cylindrica  and  plicata.  Condensing  the  results  of  these 
remarks,  we  find  the  sectional  types  of  this  sub-genus 
will  represent  all  those  of  the  entire  family,  —  and  in  the 
following  manner :  — 

Analogies  of  the  Sectional  Types  of  Theliderma. 


Sectional 
Types. 


Genera  Genera 

Analogical  Characters.  of  of 


TJninnidcE.        Unto. 

Irrorata.  Semicircular,  but  not  winged.    Unco.  Unio. 

Metanevra.  Semicircular,  and  winged.         Hyria.  ^-Eglia. 

Cylindrica.  \  ^'^^^^^SlS!"^^^'^"'' ' }  I—'  ^^-^ 

T,     .    ,  .  C  Oval ;  winged  ;  summits  very  7  \„ ^,  x 

Pustulata.  <     small  •' J  Anodon.  Lymnadiv. 

„,.     .  f  Lateral  teeth    and    cardinal  7  \,    „ „„  r> 

Pli'^ata.  ^     teeih  variable.  j  Alasmodon.  Potomida. 


Thus  we  find  that  every  thing  apparently  anomalous 
in  T.  cylindrica  is  at  once  explained  by  its  being  the 
link  between  Ligumia  and  Theliderma;  for  if  a  shell  so 
formed  had  not  been  discovered,  this  link  would  have 
been  wanting.  It  has  been  stated  that  the  crassidens, 
Peruviana,  and  rariplicata  of  Lamarck,  the  undulatus 

T 


274  SHELLS    AND    SHELL-FISH.  PART  I. 

and  crassus  of  Barnes^  and  the  undulafa  and  Domheyana 
of  Valenciennes,  are  varieties  of  Le  Sueur's  plicatus; 
but  as  no  proofs,  so  far  as  we  know  of,  have  been  brought 
forward  for  this  opinion,  we  must  withhold  our  belief 
from  it,  — more  especially  as  the  same  author  esteems  the 
Unio  sinuata  of  Lamarck  the  same  as  the  Mya  marga- 
ritifera  of  Linnaeus,  and  the  Alasmodonta  arcuata  of 
Barnes.  These  three  shells  are  now  before  us ;  and  we 
consider  them  not  only  of  difierent  species,  but  actually 
of  different  genera  :  the  first  is  a  Unio,  and  one  of  the 
types  of  Potomida;  the  two  latter  are  distinct  species 
of  Alasmodon.  Furthermore,  Lamarck  has  not  given 
the  name  of  sinuata  to  the  margaritifera  of  Linnaeus  ; 
for  he  expressly  calls  the  latter  shell,  which,  we  believe, 
is  peculiar  to  England,  Unio  elongata.  We  are  not  fond 
of  adverting  to  errors ;  but  where  they  have  been  com- 
mitted by  writers  who,  on  many  points,  deserve  honour- 
able mention,  it  is  absolutely  necessary  to  show  the 
fallacy  of  the  principles  of  arrangement  from  which 
they  have  originated.  -^ 

(257.)  On  the  remaining  sub-genera  of  Unio  —  namely, 
Cunicula,  Ligumia,  and  Megadomns,  our  remarks  must 
be  very  brief.  The  first  is  at  once  distinguished  by  the 
compression  of  the  summits  or  bosses,  and  by  being 
always  more  or  less  angulated  on  the  posterior  slope  : 
planulata,  cuncata,  and  ruhiginosa  are  typical  examples, 
having  the  lower  lateral  tooth  remarkably  thick,  —  the 
singular /o/mcm  of  Say  obviously  representing  the  Unio 
corn  at  US  ;  LRxnarck' s  pu7'j)urata  seems  to  lead  imme- 
diately to  the  sub-genus  Ligumia,  where  the  general 
form  of  the  shell  is  nearly  as  much  elongated  as  any  of 
the  Iridin^.  We  consider  Lamarck's  recta  (fig.  55.) 
as  the  type,  although  we  think  this  is  also  the  place  for 
the  gihho.m  and  other  elongated  species,  whose  outer  car- 
dinal tooth  is  not  erect,  and  both  teeth  more  in  unison 
with  those  of  Cunicula  and  Unio.  In  all  these  the  shape 
and  direction  of  the  cardinal  teeth  are  quite  different  from 

*  Lea  on  the  Genus  Unio,  Am.  Trans  vol.  iii.  N,  S.  1829. 


CHAP.   X. 


UNIONINiE.  .EGLIA. 


275 


MyscAj  which  they  nevertheless  represent  by  their  pod- 
like form.  The  remarkable  T.  cylindrica,  already  noticed, 
unites  to  this  form  the  tubercles  of  the  sub-genus  The- 
LiDERMA,  which  has  just  been  analysed. 

(258.)  There  seems  strong  evidence  for  believing  that 
our  Unio  gigas  follows  Theliderma  ;  in  which  case  it 
may  be  regarded  as  the  type  of  a  distinct  sub-genus, 
which,  for  the  present,  we  shall  name  Megadomus.  It 
diflPers  from  the  T.  Peruviana  and  its  allies,  by  having 
only  one  lateral  tooth  in  each  valve  ;  and  the  bosses  are 
remarkably  small  and  compressed.  We  have  already 
alluded  to  the  disappearance  of  one  of  the  cardinal  teeth 
in  an  aberrant  species  of  Theliderma ;  and  we  can  now 
notice  a  second  gradation  in  an  enormous  large  and  very 
old  shell,  intimately  resembling  plicata,  but  having  the 
second  lateral  tooth  in  one  valve  reduced  to  a  mere 
vestige.  The  question  is,  whether  this  deficiency  is 
accidental  or  permanent :  all  such  deviations  from  the 
typical  characters  of  the  UNioNiNiE,  particularly  in  their 
teeth,  we  regard  as  prototypes  of  the  Alasmodontin^  ; 
but  their  natural  location  is  very  difficult,  particularly 
until  the  question  regarding  Potomidea  being  a  genus, 
or  a  sub-genus,  is  decided. 

(259.)  -^GLiA,  the  second  genus,  is  the  represent- 
ative of  Hyria  :  this  is  apparent  in  the  general  form  of 
their  shells,  and  in  the  structure  of  the  cardinal  teeth. 
The  posterior  half  is  very  thick  and  truncated,  so  as  to 
form  a  carinated  angle;  the  bosses  approach  towards 
the  centre,  and  are  very  prominent;  the  form  is  thus 
almost  equilateral,  and  consequently  the  lateral  teeth  are 

T  2 


276  SHELLS    AND    SHELL-FISH.  PART  I. 

unusually  short;  the  cardinal  teeth  are  also  very  peculiar^ 
as  already  explained  (^fig.  47.  6)  ;  the  groove  between 
them  diverges  from  the  beak  in  precisely  an  opposite 
direction  to  that  which  separates  the  lateral  teeth, 
—  in  other  words,  it  is  obliquely  parallel  to  the  mar- 
gin of  the  shell,  instead  of  receding  from  it.  In  the 
comparative  size  of  these  teeth  there  is  also  a  de- 
cided difference  :  in  lEglia,  the  inner  cardinal  tooth 
is  the  smallest,  while  in  Unio  it  is  the  largest.  The 
typical  examples  are  JE.  ovata  {fig.  49.)^  cuneata  Sw., 
and  occidens  Lea.  Unfortunately,  however,  the  genus 
is  not  so  rich  in  forms  as  the  last,  and  hence  the  links 
between  the  sub- generic  types  are  not  so  beautifully 
graduated  ;  but  the  three  species  above  named  are 
certainly  typical,  and  by  means  of  ventricosa,  ater,  and 
siliqiioides,  lead  us  to  the  confines  of  the  group,  where 
we  find  such  species  as  M.  Say's  cariosiis  and  ochra- 
ceus,  among  which,  and  some  kindred  species,  there 
is  at  present  much  confusion  :  these,  however,  conduct 
us  to  the  U.  radiatus  of  the  American  conchologists. 
This  is  a  very  remarkable  shell,  because  it  seems  the  point 
of  junction  between  JEglia  and  the  next  sub-genus  (J/>/*- 
ca) ;  the  form  of  the  teeth  are  consequently  very  variable: 
hence  we  find  that,  in  some  varieties  of  this  species,  the 
teeth  are  like  those  of  ochraceus;  in  others,  the  cardinal 
teeth  are  nearly  equal,  as  in  Mysca  ;  and  in  a  very  old 
specimen  now  before  me,  the  inner  tooth  is  actually  the 
largest.  These  are  all  natural  variations,  and  are  account- 
ed for  upon  the  principle  that  osculent  groups  or  forms 
vary  according  to  the  characters  of  those  other  forms 
which  they  connect.  Lastly,  we  have  a  beautiful  pro- 
totype of  Theliderma  in  Canthyria,  the  type  of  which  is 
the  U.  spinosus  of  Lea.  This,  and  Naidea,  are  the  only 
sub-genera  we  shall  venture  to  characterise ;  the  other 
two  requiring  much  m^ore  study  than  we  have  yet  been 
able  to  give  them. 

(260.)  The  sub-genus  Mysca  follows  next,  and  ob- 
viously blends  into  the  last.  Mysca  is  the  representation 
of  Iridina  ;  and  we  consequently  find  that  nearly  all  the 


CHAP.  X. 


UNIONIN^. 


MYSCA. 


277 


species  are  unusually  long  and  narrow^  while  their  in- 
terior lustre  is  by  far  more  brilliant  and  iridescent  than 
in  either  of  the  preceding  groups.  The  cardinal  teeth, 
although  in  some  respects  like  those  of  JEglia,  neverthe- 
less deserve  much  attention,  because  they  not  only  differ 
from  those  of  Unio  and  JEglia,  but  bear  a  remote  analogy 
to  Iridina.  They  are  the  most  crenated  of  all  those 
in  the  Unionin^,  precisely  as  those  of  Iridina  are  the 
most  crenated  in  the  entire  family  :  they  are  likewise  the 
most  parallel  to  the  anterior  margin;  and  although  in 
general  distinctly  divided,  they  yet  have  a  propensity, 
even  in  individuals  of  the  same  species,  to  unite,  and  run, 
as  it  were,  into  each  other  ;  so  that  in  some  specimens 
of  our  Mysca  ovata  (Jig.  66.),  these  two  teeth  will  be 


perfectly  divided ;  while  in  others  of  a  younger  age,  from 
the  same  pond,  the  division  will  be  only  marked  by  an 
indentation  on  the  ridge,  —  the  groove  itself  being  almost 
obsolete.  Now,  this  is  precisely  in  unison  wdth  shells 
intended  to  represent  Iridina,  where  the  lateral  and 
cardinal  teeth  are  united  into  a  crenated  line.  This  vari- 
ation in  shells  of  the  same  species  is  not  only  perplexing 
to  young  conchologists,  but  to  more  experienced  ones  : 
in  general,  however,  we  may  consider  it  as  a  rule  that  no 
Unio  belongs  to  this  group,  which  has  the  cardinal  teeth 
thick  and  obtuse  ;  nor  does  it  comprise  any  in  which  one 
of  the  cardinal  teeth  is  not  immediately  beneath  the 
bosses.  These  positive  and  negative  characters  render 
the  discrimination  of  Mysca  comparatively  easy.     Very 

T   3 


278  SHELLS    AND    SHELL-FISH.  PART  I. 

fortunately,  the  group^  although  not  so  extensive  as  the 
firstj  is  yet  rich  in  subordinate  types  ;  we  shall,  there- 
fore make  some  approximation  to  the  natural  series  of 
the  species,  by  looking  to  the  following  table,  wherein 
each  subordinate  type  is  indicated  by  its  most  prominent 
example. 

Analogies  of  the  Sub-generic  Ti/pes  of  My sc a. 

rr,  4     1-  Genera  of 

^yP'''  Analogies.  Unionidcc. 

Mv«caovata  f  Both  cardinal  teeth  presentj-^hort,  7         ^1*10 

Myscaovata.  ^     and  jaggedjoue  in  the  left  valve,  j         ^^''^• 

^„ .     i-T  CTwo  nearly  equal  cardinal  teeth  7         «..„,» 

marginahs.  J     in  the  left  valve.  j         "^^'^• 

nasufa  I"  ^"^^"^  cardinal  tooth  nearly  erect,  )         TR,nivA 

nasuta.         ^     pointed,  somewhat  conical.        j         iridina. 

Nilotira        ("Oval;  hinge  sub-connate;  poste- 7  Anodox 

JNllotica.       ^     rior  angle  winged.  j         anodox. 

f.      .,.      '     f  Hinge  sub-connate:  eardinalteeth  7         a,.,,,^„^„ 
fragihs.         I     infperfect.  j         ALAbMODON. 

(261.)  Among  the  longest  species  of  Mysca  generally 
known  are  our  two  British  species,  ovata  and  pictorum, 
which  may  consequently  be  considered  typical;  and  these 
also  have  the  most  crenated  cardinal  teeth.  Following 
these  we  have  a  type  from  India, represented  by  the  mar- 
ginalis  of  Lamarck,  where  the  outer  cardinal  tooth  is  long 
and  slender,  as  in  Hyria;  and  the  other  similarly  formed, 
but  much  shorter :  these  shells  are  also  remarkable  for 
having  two  distinct  cardinal  teeth,  almost  alike,  in  the 
other  or  left  hand  valve, —  a  structure  which  is  quite 
different  from  that  of  ovata,  and  indeed  of  all  other 
Unionidce.  Let  the  malacologist  examine  the  Hyria 
avicularia  and  the  Unio  marginata  of  Lamarck ;  and 
so  far  as  regards  the  cardinal  teeth,  he  will  find  they  are 
formed  precisely  on  the  same  model  :  nothing,  there- 
fore, can  be  more  perfect.*  Marginalis  agrees  also  with 
Iridina,  in  being,  without  exception,  the  most  iridescent 

•  We  even  question  whether  this  may  not  be  a  relation  of  affinity,  and 
thus  Lamarck's  marginata  may  be  the  anodontine  type  in  Hyria. 


CHAP.   X.  UNIONIN^.  MYSCA.  279 

of  the  group  :  with  mnrginalis  must  be  joined  three  or 
four  other  species,  all  of  which  are  from  China  and 
India.  One  of  these  now  before  us,  bears  such  a  close 
resemblance  to  the  Unio  nasutus  of  Say.  that,  if  the  teeth 
are  not  examined,  it  would  be  impossible  to  define  their 
difference.  Nasutus,  however,  represents  another  type, 
which  at  present  is  almost  exclusively  confined  to  North 
America.  Here  the  cardinal  teeth  greatly  resemble  those 
of  Say's cario^rt  and  radiata  (which  come  into  the  circle  of 
jSIglia)  ;  for  the  outer  one  is  somewhat  conic  and  erect, 
while  there  is  only  a  single  defined  tooth  in  the  left  valve. 
From  nasuta  we  pass,  by  several  intervening  species, 
into  the  next  type,  represented  by  onr  M.Nilotica,  shaped 
like  a  small  Anodon,  but  with  the  teeth  of  Mysca.  We 
possess  three  other  species,  all  from  the  river  Nile,  and 
believe  there  are  many  others.  Finally,  we  have  from 
America  the  Unio  fragilis,  figured  very  accurately  in  our 
Zool.  Illust.  1st  Series,  pi.  17 1^  I'ut  which  the  Ameri- 
can conchologists  do  not  appear  to  understand  :  it  truly 
belongs  to  their  genus  Unio,  because  the  two  lateral  teeth 
are  well  defined,  although  the  cardinal  are  but  slightly 
developed.  Our  figure,  nevertheless,  was  drawn  from  a 
very  old  specimen,  which  did  not  exhibit  the  elevated  and 
angulated  posterior  margin.  Now,  of  all  the  UnionidcB 
so  constructed,  this  makes  the  nearest  approach  to  the 
well-known  Unio  alata  of  Lamarck ;  while,  in  the  imper- 
fection of  its  teeth,  it  clearly  represents  Alasmodon. 
We  are  thus  brought  round  to  the  group  with  which  we 
commenced  ;  and  were  it  necessary  to  point  out  the 
precise  point  where  the  circle  is  closed,  Ave  could  expa- 
tiate upon  the  structure  of  our  M.Mexicana, — an  unde- 
scribed  species,  and  standing  intermediate  between  the 
first  type  and  the  last.  It  must  not  be  supposed  that  the 
modifications  of  form  represented  by  the  five  species 
named  in  the  last  table,  are  merely  confined  to  one  or  two 
examples ;  even  our  own  collection  of  specimens  and  of 
drawings  can  produce  several,  Ovata,  for  instance, 
represents  a  little  group  of  eight  species ;  marginalis, 
another  of  four;    nasuta,  seven;    JVilotica,  four;   and 

T  4 


280  SHELLS    AND    SIIELL-FISH.  PART  I. 

fragiUs,  two.  Now^  when  we  reflect  how  many  more  may 
be  in  cabinets^  and  the  probability  of  still  greater  num- 
bers being  midiscovered^  we  should  be  fully  waranted  in 
designating  these  sections  as  sub-genera ;  but  so  long  as 
any  doubts  remain  regarding  the  true  affinities  of  our 
sub-genus  Potomida,  this  plan  may  be  suspended. 

(2()2.)  The  Lymnadia  alata  is  one  of  the  most  re- 
markable shells  of  this  sub-family ;  not  so  much  on  ac- 
count of  its  beauty^  but  as  holding  a  more  isolated  station 
than  any  yet  noticed.  That  it  has  a  strong  resemblance 
to  Anodon,  is  indisputable  ;  but  that  it  has  a  much 
stronger  one  to  the  Unionince,  cannot  be  questioned.  — 
Now,  every  one  who  draws  the  distinction  between 
analogy  and  affinity^  immediately  perceives  that  the  first 
of  these  resemblances  is  purely  analogical;  w'hile  the 
other,  as  Lamarck,  Say,  and  Barnes  have  correctly 
judged,  is  one  of  absolute  aflSnity  :  it  is  needless,  there- 
fore, to  discuss  this  matter  further.  At  present,  Lym- 
nadia alata  (fig.  48.)  stands  almost  alone  as  the  repre- 
sentative of  that  sub-genus  which  typifies  the  anodons. 
In  conformity  with  this  analogy^  we  find  the  posterior 
dorsal  margin  remarkably  elevated,  dilated,  and  winged. 
The  ligament  also  is  connate, — that  is,  entirely  covered 
by  a  prolongation  of  the  testaceous  substance  of  the  valves: 
the  bosses  small,  and  the  shell  itself  oval  and  depressed. 
The  cardinal  teeth  are  very  peculiar  :  they  are  compressed 
and  crenated  like  those  of  Mysca  ;  but  the  inner  one  is 
generally  the  largest;  and  the  direction  of  the  groove  which 
separates  them,  is  either  perpendicular,  or  diverges  from 
the  anterior  margin  of  the  shell.  It  is  clear  that  our  Unio 
fragilis*  either  enters  in  this  group  or  is  at  the  confines  of 
the  last:  the  next  question  is,  what  others  can  be  arranged 
in  the  same  genus  with  Lymnadia  ?  We  entertain  little 
doubt  that  the  Symphynota  compressa  of  ]\Ir.  Lea  is  one  of 
these. f  In  this  curious  type,  the  cardinal  and  the  lateral 
teeth  are  perfect,  and  it  has  the  complete  external  aspect  of 

•  Zool.  111.  1st  Series,  pi.  171. 

f  We  only  know  this  from  the  very  excellent  description  and  figure  in 
Mr.  Lea's  paper. 


CHAP.   X. 


UNIONIN^. 


LYMNADIA. 


281 


Anodon :  it  is  also  so  perfectly  connate^  that  Mr.  Lea,  look- 
ing only  to  that  circumstance,  actually  places  it  close  to 
L.  alata.     It  is  nevertheless  a  distinct  type,  and  seems  to 
represent  Anodon  in  this  sub-genus  :   the  cardinal  teeth, 
in  short,  strengthen  us  in  the  belief  that  Pofomida  suc- 
ceeds to  Lyynnadia.   We  shall  therefore  introduce  it  here, 
leaving  its  natural  affinities  still  open  to  future  inquiry. 
(263.)   In  regard  to  the  shells  provisionally  placed  in 
the  genus  Potomida,  we  have  some  doubts.    We  feel  al- 
most convinced  that  the  types  do  not  belong  to  the  genus 
Myfica  ;  and  yet  some  of  the  aberrant  species  approach 
so  closely  to  such  shells  as  M.  pictorum  and  ovata,  that 
the  gradation,  to  ordinary  eyes,  appears  perfect.    We  have 
one  or  two  species  from  Brazil,  and  others  from  North 
America,  but  most  of  the  types  seem  to  be  European 
These  present  us  with  the  following  distinguishing  charac- 
ters :  the  form,  of  course,  is  variable  in  the  species ;  but 
it  is  never  so  long  and  attenuated  a.s 3fysca;  the  breadth, 
also,  is  greater,  and  the  extremities  more  obtuse.   The  ty- 
pical species,  P.  corrugata 
(  ^^.57.):'isnearly  asround 
as  the    generality  of   the 
Venus -shells :  the  cardinal 
teeth  are  always  two,  —  not 
thin,  lengthened,  and  com- 
pressed as  in  Mysca,  but 
thick,  short,  and  strong,  so 
as   to    resemble    the    true 
American  unios ;  like  these  latter,  also,  the  inner  cardinal 
tooth  is  decidedly  the  largest  —  but  then  they  are  divided 
like  those  of  Mysca  and  ^glia.    The  size  of  the  teeth, 
with  the  general  shape,  and  robustness  of  the  shell,  in- 
duce us  to  think  that  Potomida  is  not  naturally  associated 
with  either  Mysca  or  Unio.     The  littoralis  of  Lamarck, 
common  in  the  rivers  of  France,  w411  show  all  these  cha- 
racters ;  but  in  another  Continental  species,  the    Unio 
sinuata  Lam,,  the  form  is  more  lengthened  ;  and  by  the 
direction  of  the  cardinal  cleft,  this  shell  seems  to  approxi- 
mate still  more  to  the  typical  Unios.    Next  we  have  the 


282 


SHELLS    AND    SHELL-FISH. 


PART  I. 


Unio  hatava  of  the  same  country^  where  the  teeth  begin  to 
resemble  those  of  My. sea;  but  they  are  still  short,  strong, 
thick,  and  distinctly  separated.  Proceeding  thus  in  the 
natural  series,  without  caring  to  circumscribe  our  groups 

by  arbitrary  characters, 
we  come  to  P.  Sicula 
{fig.  58.),  a  new  spe- 
cies, found  by  us  in  the 
lakes  of  Leontini  in 
Sicily  :  here  we  have  a 
still  nearer  approach  to 
Mysca  than  what  is  made 
by  Batata  :  the  form  of 
the  shell,  indeed,  is  that  of  Mysca  ovata;  but  the  teeth 
are  still  thick,  and  the  inner  one  still  preserves  the  typi- 
cal character  of  being  thicker  than  the  other.  The  P. 
elongata,  also  from  Sicily,  would  seem  to  complete  the 
union  of  this  sub-genus  with  Mysca.  Whether  we  are 
to  look  to  this  as  the  union  of  the  three  aberrant  genera 
of  the  UnionincB  into  one  circle,  or  to  take  it  as  pre- 
sumptive evidence  that  these  shells  form  only  a  division 
of  Mysca,  is  uncertain.  The  question  is,  are  they  really 
distinct  types  }  If  we  merely  look  to  Mysca  pictoruni  or 
ovata,  and  Potomida  litoralis  or  corrugata,  the  differ- 
ence is  very  remarkable  ;  but  on  placing  between  them 
Potomida  Batava,  Sicula,  and  elongata,  the  extreme 
differences  are  softened  down,  and  we  become  doubtful 
as  to  the  limits  of  the  group.*  There  are  several  North 
American  shells  which  we  suspect  will  clear  up  this  point, 
and  hereafter  enable  us  to  discover  the  true  typical  cha- 
racters. 

(264.)   The   HyRiNiE  constitute  a   small  but   very 
distinct  sub-family,  remarkable  both  for  its  characters 

*  Our  collection  of  Unionid(e,  upon  which  these  remarks  were  founded, 
has  unfortunately  passed  into  the  hands  of  others,  and  prevents  us  from 
again  investigating  this  (|uestion.  We  shall  feel  particularly  iiidchted  to 
those  conchologists  of  America  who  study  the  Unionidcv,  for  specimens,  ac- 
curately named,  from  their  "  Western  Waters,"  of  all  the  species  they  can 
part  with,  promising  to  return  others  in  exchange,  from  \ow  Ze.iland. 
Letters  and  parcels  should  be  directed  to  us,  to  the  care  of  John  Willis, 
Esq.,  Liverpool. 


CHAP.   X.  HYRIN^.  283 

and  its  geographic  distribution.  All  the  species  yet 
known^  are  from  the  rivers  of  Tropical  America  and 
Australia,  —  not  one  having  been  found  north  of  the 
line.  Indeed,  it  may  be  almost  said  that  the  range  of 
the  genus  Unio  is  bounded  by  the  same  latitudes  ;  for 
of  all  the  UNioNiNiE  we  have  yet  seen,  not  more  than 
two  have  been  brought  from  South  America,  and  these 
do  not  belong  to  the  most  typical  groups.  The  Hv- 
R1N.E  are  distinguished  by  the  angulated  or  wedge- 
shaped  form  of  the  shell,  and  the  winglike  projection 
of  its  hinge  or  dorsal  extremities.  The  second  cha- 
racter is  in  the  narrow  linear  form  of  the  cardinal 
teeth,  w^hich  are  on  one  side  of  the  bosses,  not  beneath 
them  :  these  teeth  also  diverge  to  the  anterior  edge, 
and  are  always  more  or  less  linear.  The  third  cha- 
racter is  so  very  simple  and  constant,  that  it  may  be 
recognised  by  the  merest  tyro ;  the  bosses  or  summits 
of  the  valves  are  wrinkled  or  grooved  transversely  ;  that 
is,  in  a  line  from  the  apex  to  the  basal  margin.  This 
singular  peculiarity,  which  pervades  nearly  all  the  types 
we  have  yet  seen  of  the  Hyrin^,  is  directly  opposed  to 
the  characters  of  the  Unionin^,  where,  if  the  summits 
are  wrinkled,  the  wrinkles  are  placed  longitudinally,  or 
in  a  direction  from  the  anterior  to  the  posterior  ex- 
tremities. In  what  way  this  may  be  connected  with 
the  natural  habits  of  the  animals,  is  totally  unknown. 

(265.)  The  passage  from  the  UiSioNiNiE  to  the  Hy- 
RiN^  is  through  Mysca  in  the  former,  and  Iridea  in 
the  latter.  The  gradation  from  one  to  the  other  is 
beautifully  perfect.  Iridea  has  the  strongest  possible 
affinity  to  Mysca^  in  the  general  shape  of  the  shell,  and 
in  the  structure  of  the  cardinal  teeth  :  the  form,  how- 
ever, is  more  oval  than  elongated ;  the  ends  more 
obtuse ;  the  posterior  end  of  the  hinge  margin  more 
elevated,  and  the  summits  smaller.  These,  however, 
are  points  of  inferior  moment.  The  chief  distinction 
is  in  the  length  and  narrowness  of  the  outer  cardinal 
tooth,  and  the  almost  total  absence  of  the  other :  hence 
it  is,  that  in  such  shells  there  are  always  two  distinct 


28-i 


SHELLS    AND    SHELL-FISH. 


PART  I. 


cardinal  teeth  in  the  left  valve  ;  whereas,  in  the  Unio- 
-sisM,  this  valve  has  scarcely  ever  more  than  one. 
When,  however,  both  are  present  in  the  right  valve, 
the  inner  one  is  always  under,  and  not  on  the  same 
line  or  on  the  side  of  the  outer  tooth.  The  most 
aberrant  species  of  Mysca  have  something  of  this  ap- 
pearance, not  very  apparent  to  young  conchologists. 
But  there  is  another  and  a  more  easy  discrimination. 
Of  thirteen  species  of  Iridea  now  before  us,  each  and  all 
have  the  bosses  or  umhones  wrinkled  transversely,  as 
in  Hyria.  We  cannot,  indeed,  expect  that  every  species 
will  be  so  marked,  for  then  there  would  be  an  absolute 
line  of  demarcation  between  Iridea  and  Mysca,  which 
is  contrary  to  nature  ;  but  the  facts  now  stated  will 
enable  any  one  to  discriminate  the  two  types.  The 
next  sub-genus  is  Lamarck's  Castalia,  of  which  but 
one  species  is  generally  known.  Reasoning  from  ana- 
logy, it  follows  Iridea  ;  but  if  so,  the  minor  types  of 
connection  are  wanting.     It  is  a  cockle-shaped  shell, 

nearly  equilateral,  and 
59  bears  a  strong  resem- 
blance to  JEglia  cune- 
ata.  From  this  rare 
and  somewhat  isolated 
type  the  transition  to 
Hyria  (fig.  5^.)  is  ren- 
dered easy  and  natural 
by  means  of  Hyria  cor- 
rugata  Lam.  ;  and  Hy- 
ria elongata  indicates  a  passage  to  that  elongated  form 
which  has  not  yet  been  discovered,  and  which  must 
represent  either  Alasmodon  or  Iridina^  Such  a  shell 
we  remember  to  have  once  seen  at  King's  Auction- 
rooms,  but  by  some  accident  neglected  to  take  notes,  or 
to  secure  the  specimen.  In  the  sub-genus  Na'ia,  which 
we  arrange  under  Castalia,  we  have  a  form  connecting 
the  C.  cordata*   with  Iridea.     AV^e  have  before  us  six 


*  I  use  the  prior  specific  name  of  Ilumplircy  rather  than  Lamarck's 
ambigua,  which  throws  an  unnecessary  tioubt  on  its  being  a  species. 


CHAP.   X.  HYRIN^  AND  UNIONINiE.  Og^ 

species,  four  of  which  are  from  India_,  and  two  from 
Australia.  They  are  short,  roundly  oval  shells,  with 
the  umbones  well  defined,  and  placed  tow^ards  the 
middle:  from  this  results  their  peculiar  character.  The 
lateral  teeth  are  short,  and  not  a  great  deal  longer  than 
the  cardinal  teeth  ;  these  latter  being  strong  and  thick, 
without  being  short :  they  are  much  crenated,  yet 
without  any  ridge  ;  so  that  they  have  the  appearance  of 
being  broken  off.  Their  immediate  affinity  to  Tridea 
is  proved  by  the  Na'ia  elongata,  from  New  Holland, 
having  the  form  of  one  type,  and  the  teeth  of  the  other. 
This  interesting  species,  once  the  property  of  admiral 
Bligh,  was  purchased  by  us  at  his  sale.  The  pecu- 
liarities of  Lamarck's  Unio  Australis  (^Hyridella  Sw.), 
and  its  affinity  to  Iridea,  lead  us  to  arrange  it  as  the 
anodontine  type  of  the  Hyrian^,  although  it  may  pos- 
sibly be  an  aberiant  example  of  Iridea :  the  bosses,  how- 
ever, are  not  striated,  and  the  wdiole  shell  has  very  much 
the  aspect  of  an  Anodon.  Of  the  fifth  type,  connecting 
this  sub-family  to  the  next,  we  know  nothing  more  than 
what  has  been  already  stated.  As  the  remaining  genera 
of  the  Unionidce  are  neither  rich  in  the  number  of  their 
forms,  nor  abundant  in  their  species,  we  shall  mention 
them  wath  more  conciseness. 

(266.)  According  to  the  views  here  taken  of  the 
Hyrin^,  we  may  thus  compare  the  four  genera,  just 
defined,  with  the  circle  of  the  Unionin^. 


Analogies  of  the  Hyrin.e  and  the  Unionin^. 

Genera  of  the                         j„„7^„,-„o  Genera  of  the 

HyriiiLe.                                       *'  Lnioni/ue. 

r^.om.T..                  CShell     trigonal:    posterior    side^  zc^t.. 

Castalia.                J     truncate  and  short.                      j  ^^«"^- 

Hyria.                       Posterior  side  lengthened.  Unio. 

. ?  POTOMIDA, 

TT          ^                     ("Compressed,   broad:    bosses   not7  t, .......... 

Hyridella.             I     striated,  retuse ;  teeth  slender.]  Lymnadia. 

C  Lengthened  oblong ;  bosses  small;  "i 

Iridea.                     <      inner  cardinal  teeth  very  small,  >  Mysci, 
C.     almost  obsolete.                          J 


286 


SHELLS    AND    SHELL-FISH. 


PART  I. 


The  type  which  we  consider  unknown,  is  that  which 
leads  immediately  to  Iridina,  and  would  consequently 
be  deficient  in  some  of  the  teeth.  The  other  four  are 
such  obvious  representations  of  their  prototypes  among 
the  Unionin^,  that  we  need  not  detain  the  reader  by 
any  additional  remarks. 

(267.)  Of  the  iRiDiNiE,  only  three  typical  species  have 
been  yet  discovered ;  and  these,  we  believe,  are  all  from 

the  river  Nile.  (/.  elongata, 
fig.  60.)  The  form  of  the 
whole  group  has  been  before 
stated  ;  the  shell  is  almost  of 
equal  breadth  throughout, 
with  the  posterior  end  nearly, 
if  not  quite,  as  broad  as  the 
anterior.  This  great  elongation  of  the  shell  must  extend, 
of  course,  to  the  animal;  and  for  this  reason  we  admit 
into  the  genus  Iridina  a  singular  shell  from  the  same 
river  {Iridina  Nilotica  Fer.),  but  which  has  the  hinge 
line  only  '^^  slightly  crenulated  at  the  umbones."*  Here 
it  is  that  Nature,  as  it  were,  is  hovering  between  the 
confines  of  this  type  and  the  Anodontince,  and  plainly 
intimates  to  us  which  will  be  her  succeeding  group. 

(268.)  The  ANODONTiNiB  form  a  more  numerous 
sub-family  than  the  two  last.  Tropical  America  ap- 
pears richer  in  these  shells,  than  any  other  part  of  the 
world.  Although  one  of  the  sub-genera  is  peculiar  to 
Asia,  the  typical  form  (represented  by  our  common 
Anodon  anatinus)  occurs  both  in  Europe,  Asia,  and 
North  America,  but  under  different  modifications,  which 
will  render  it  necessary  to  distinguish  them  as  sub-ge- 
nera. We  arrange  the  whole  under  the  five  principal 
genera  of  Lamproscapha  Sw.,  Symphynota  Lea,  Anodon 
Lam.,  Hemiodon  Sw.,  and  Patularia  Sw.  The  first  of 
these  contains  such  shells  as  the  A.  ensiformis,  siliquo- 
sum,  &c.f ,  which  have  the   shape  of  Iridina,  but  are 

•  Zool.  Journ.  i.  55.  The  name  of  Pleodon  cannot  be  substituted  for  that 
of  Iridina,  as  applied  to  the  typical  species. 

+  From  Brazil,  figured  in  Spix  and  Martius's  Testacca  Fhiviatilia,  SjC^ 
published  in  1827. 


CHAP.  X.  IBIDIN^.  —  ANODONTIN^.  287 

destitute  of  any  crenations^  or  plate,  below  the  hinge  mar- 
gin. These  obviously  lead  io  Symphynota,  where  the  form 
is  oval  and  winged ;  while  a  slender  lamellar  tooth  ex- 
tends the  whole  length  of  the  shell.  Following  this  we 
have  the  typical  genus  Anodon,  where  the  plate  in  ques- 
tion is  entirely  wanting.  There  are  many  striking  mo- 
difications, however,  in  the  form  of  these  shells,  which 
may  hereafter  point  out  the  sub-genera:  —  in  Anodon 
proper,  the  form  is  transversely  oval  or  oblong,  and  the 
bosses  very  small  and  compressed;  Patularia  has  the  um- 
bones  remarkably  swollen,  or  ventricose ;  and  the  shell 
almost  round:  lastly, the  genus  Hemiodon  includes  those 
which  have  a  slight  tubercle,  or  indication  of  the  car- 
dinal teeth;  thus  leading  to  the  Alasmodontiiv^. 

(269.)  Assembling  these  types  in  a  tabular  form,  we 
shall  find  they  possess  the  usual  analogies. 

Analogies  of  the  Genera  of  the  Anodontin^. 

Genera  of  the  a„^i„  -^r.  Sub-fatnilies  of 


AnodontincE. 


Analogies.  Unionida. 


Anodo\.  Pre-eminently  typical.  Unionin^. 

Symphynota.  Hinge  margin  or  tetth  lamellar.      Hyrian^e. 

T    „„„.„„  (■  Boat-shaped,  and  very  long,  no7T„     

Lamproscapha.      <     teeth  j        o  >        i  Iridinan^. 

Patularia.  '  Shell  nearly  round  ;  no  teeth.  Anodonin^. 

Vr'        „^„  f  Hinge  plate  sinuated  or  tubercu-  7  . , 

Hemiodon.  <     lated  I  ALASMODONiNiE. 

Not  having  carried  our  analysis  into  the  sub-genera, 
we  shall  not  venture  to  name  those  which  have  the 
aspect  of  being  such.  It  is  plain,  however,  that  there  are 
aberrant  species,  if  not  sub-genera,  in  Symphynota  and 
Anodon.  These  two  are  probably  connected  by  Anodon 
rubra,  which  has  a  distinct  elevated  ridge,  analogous  to 
the  lamellar  tooth  of  Symphynota.  The  bosses,  again, 
of  our  common  Anodon  are  small  and  compressed;  while 
those  of  A.  trapezialis  Lam.,  and  other  large  species, 
are  remarkably  ventricose.   The  Anodon  purpurascens* , 

*  Zool.  111.  pi.  i.  260. 


288 


SHELLS    AND    SHELL-FISH. 


PART  I. 


again^  has  the  rudiments  of  a  very  thin  and  short  lateral 
plate.  It  may  be  proper  to  observe  in  this  place,  that 
Dipsas  was  the  original  name  imposed  by  Dr.  Leach  to 
this  sub-genus  ;  but  Larentini,  so  far  back  as  1768,  had 
given  this  name  to  a  genus  of  reptiles :  and  as  this  is 
an  insuperable  bar  to  its  repetition,  we  gladly  adopt  that 
of  Symphynota  Lea,  under  the  restrictions  here  men- 
tioned. 

(270.)  The  last  sub-family  is  that  of  the  Alasmo- 
DONTiNiE,  the  typical  species  of  which  are  all  from  the 
rivers  of  America.  They  are  connected  to  the  anodons, 
in  the  most  graduated  and  perfect  manner,  by  our  genus 
Hemidon;  and  the  first  type  is  probably  represented  by 
the  Unio  calceola  of  Lea  :   then  follows  the  typical  form, 

as  seen  in  Say's  original 
Alasmodon  undulata 
{Jig.  61.);  our  genus 
Uniopsis  appears  to  suc- 
ceed this ,  then  we  have 
the  elongated  form  in 
Schumacher's  Margari- 
tana;  and,  finally,  the 
anodoniform,  or  most 
aberrant  type,  is  seen  in 
our  Complanai'ia  gigas  and  rugosa*  The  whole  of  these 
constitute  one  of  the  most  natural  divisions  in  the  family. 
Typically  considered,  they  are  without  any  distinct  lateral 
teeth  ;  the  hinge-plate  being  either  long  and  merely  con- 
vex, as  in  Margaritana ;  or  short,  flattened,  and  obliquely 
grooved,  as  in  Complanaria.  The  cardinal  teeth  are 
always  present,  but  vary  in  each  type ;  hence  they  fur- 
nish an  admirable  clue  to  the  analogies  of  the  genera. 
Nothing  appears  known  of  the  animal;  but  this  is  not 
material  to  our  present  purpose,  since  the  variation  of 
the  shell  is  quite  sufficient  to  guide  us  in  their  natural 


*  Mr.  Lea,  in  his  artificial  arrangement,  i)laces  these  two  shells  in  widely 
different  divisions,  because  one,  he  says,  is  "  syniphynote,"  and'  the  other 
'•  7to«-synii)hynote:i"  they  are  the  Alasrnodonta  coniplanata  and rugosa  of 
American  writers,  and  are  most  naturally  connected. 


CHAP.  X. 


ALASMODONTIN^. 


289 


arrangement.  The  ex- 
ceedingly oblique  teeth 
of  our  Uniopsis  radiata* 
(Jig.  62.)  show  it  is  the 
prototype  of  Unio,  and 
might  have  been  there 
placed,  but  for  the  want 
of  lateral  teeth.  The 
triangular  and  cuneated 
shape  of  Alasmodon  un. 
dulata  reminds  us  of 
^glia.  The  single  cardinal  tooth  of  Calceola  t7'uncataf 
accords  with  the  tubercles  of  Hemiodon;  while  the 
compressed  bosses  and  dilated  posterior  side  of  Compla- 
naria  preserves  the  analogy  between  this  sub-genus  and 
its  prototypes  Lymnadia,  T^heliderma,  and  Anodon. 
Finally,  we  come  to  Margaritana,  which,  every  one 
must  perceive,  puts  on  the  aspect  of  Mysca,  Ligumia, 
Potomida,  and  the  Iridince.  Wliether  the  whole  of 
the  shells  retained  by  us  in  this  last  genus  really  enter 
into  the  circle  we  are  at  present  tracing,  or  that  such 
as  have  an  obsolete  lateral  tooth  should  naturally  be 
arranged  with  the  Potomida  Uttoralis^  &c.,  cannot,  of 
course,  be  yet  determined ;  nor  do  we  feel  certain  that 
Calceola  is  the  connecting  type  with  the  AnodontincB. 
And  yet,  as  all  these  find  their  representatives  in  the  lead- 
ing divisions  of  the  Unionid^,  they  become  absolutely 
types  of  genera,  equivalent  in  rank,  although  not  in 
numbers,  to  the  genera  of  the  sub-family  Unionin^. 
This  will  be  further  apparent  from  the  following  expo- 
sition :  — 


*  I  suppose,  from  the  name,  that  this  is  the  Margaritana  radiata  of 
Lea's  Synopsis,  but,  as  no  reference  is  made  to  where  the  shell  is  described, 
or  any  information  beyond  its  being  "  non-symphynote  and  smooth,"  I 
affix  this  name  at  a  venture,  merely  for  my  present  purpose;  the  real  name, 
if  described,  can  always  be  made  out  from  the  figure  here  given.  Since 
writing  the  above,  my  kind  friend  Mrs.  Corrie  (who  has  a  noble  series  of 
Unionidce  in  her  fine  collection)  has  sent  me  a  specimen  of  this  type  under 
the  name  of  Alasmodon  inflata  ;  the  teeth  are  not  near  so  oblique  as  in  that 
here  figured. 

t  Under  the  common  name  of  XJnio  calciolus,  we  have  received  three 
distinct  species  from  America. 


U 


290 


SHELLS    AND    SHELL-FISH. 


PART   I. 


Analogies  of  the  Genera  of  the  ALASMODONTiNiE. 

Genera. 


Analogical 
Characters. 

f  Inequilateral  ;"| 
I  the  cardinal  | 
teeth  reced-  [ 


Sub-families 

of  the 

Unionidcc. 


Genera      Sub-genera 
of  of 

Unionince.        Unio.    ^ 


Uniopsis.  ^     ing'from^he  ^  ^^■"^^''^^-  ^^^^-  ^"'''• 

j     anterior         j 
L    margin.         J 

rCuneate,    andT 
Alas7?iodon.      <     nearly  equi-  ^  Hyrin^.  JEglja.  Cunicula. 

C.     lateral.  J 

Calceola.  ?  Alasmodoninjs.  Potomida.    Megadomus. 

Winged ;    the" 
Complanaria.  -{     !?2!f ^®  l™^u />  ANOooNTiNa;.     Lymi^ Am\.   Theliderma 


S  Winged ;    the") 
bosses  small  ( 
and      much  T  ^ 
compressed.  3 
f  Oblong     oval,-! 
Margaritana.  ]     greatly  Mridin^. 

C     lengthened.  J 


MyscA.         Ligumia. 


(271.)  Having  brought  our  rapid  exposition  of  this 
family  to  a  close,  we  may  now  offer  a  few  general  re- 
marks upon  the  whole.  The  Unionidcs,  of  all  the  groups 
of  the  DiTHYRA,  is  that  which  contains  the  greatest 
modifications  of  form  ;  insomuch  that  it  becomes 
almost  impossible,  in  some  of  its  minor  divisions,  to 
determine  which  are  species,  and  which  varieties. 
Hence  has  originated  the  idea,  entertained  by  several 
conchologists,  that  they  constitute  but  a  single  genus  ; 
while  others  have  gone  so  far  as  to  suspect  that  there 
is  in  reality  but  one  species  of  Unio,  and  "  perhaps  of 
the  whole  family  :  "  such,  at  least,  were  the  sentiments 
entertained  some  years  ago,  although  we  believe  they 
'no  longer  exist.  Upon  this  principle,  the  equally  ex- 
tensive and  varied  family  of  HelicidfE  should  form  but 
one  genus,  or  rather  but  one  species,  which  might  be 
called  Helix  or  Limax  terrestris,  because  it  lived  upon 
land.*  It  is  useless  to  prove,  that  by  this  false  and 
vicious  sort  of  generalisation,  we  should  return  back  to 

*  The  naked  slugs  and  the  land  snails  pass  into  each  other  by  such  gra- 
duated shades,  that  no  "  well-marked  and  absolute  characters"  can  be 
found  to  separate  them. 


CHAP.  X.  ALASMODONTINiE.  291 

the  dark  ages  of  zoology,  and  produce  the  same  sort  of 
confusion  and  ignorance  which  then  reigned.    But,  then, 
it  may  be  asked,  how  can  genera  be  retained  in  our 
systems,    which    actually   blend    into   each   other,  and 
whose  distinctions  thus  become  lost  ?      This  objection 
has  been  repeatedly  answered.    Genera  which  are  really 
natural,  are  always  thus  united,  because  they  show  us 
all  the  connecting  links  of  nature.     But  genera  which 
contain  only  well-defined    and    isolated   characters,   so 
that  no   ordinary  person   can   confound    them,    are  not 
perfect,  because  their   connecting   links    to  others  are 
wanting :    they  are  fragments   of  the  chain,  having  its 
gradations  disturbed,  dissevered,  broken  ;  —  hence  such 
groups  are  fragments  only  of  what  has  been,  or  may  be, 
a  natural  assemblage.     Our   divisions  of  sub-families, 
genera,  sub-genera,  and  sections,  are  mere  conventional 
terms  employed  to  denote  groups  of  different  sizes,  pos- 
sessing, in  the  majority,  certain  primary  characters  which 
are   termed  typical.      It   matters   not  upon  what  cha- 
racters  these   divisions   are  founded   in   the    Unionidce 
and  the  HelicidcB,   provided  none   can   be  drawn  from 
the  animal ;  but  it  is  most  essential  that  disruptions  of 
kindred  species  should   not  be  made,  —  for  then    the 
harmony  of  nature   is   destroyed.     Now,  this  leads  us 
again  to  advert  to    the   different  sorts  of  resemblances 
natural  objects  bear   to   each   other.     The  confounding 
of  analogy  and   affinity,  which  has  led  to   the  greatest 
confusion  in  every  branch  of  zoology,  has  been  particu- 
larly conspicuous  in  this  :    every    conchologist,  for  in- 
stance, perceives  that  Ligumia  recta,  Mysca  ovata  and 
nasuta,  Iridina  elongata,  and  Alasmodon  margaritifera , 
have  a  very  strong  resemblance  to  each  other.     Now,  if 
this  resemblance  were  one  of  affinity,  it  naturally  would 
follow  that  all  these  shells  belonged  to  the  same  natural 
group  :  they  possess  one  character  in  common,  —  that  of 
being  particularly  long,  pod-like  shells ;  yet  if  any  me- 
thodist,  looking  to  this  only,  and  disregarding  all  other 
characters,  make  them  into   a  genus,  he  would  commit 
a  palpable  outrage  on  natural  classification.     So,  in  like 

w  2 


292  SHELLS    AND    SHELL-FISH.  PART  I. 

manner,  if  he  took  all  the  winged  or  connate  shells, 
and,  holding  as  trivial  their  other  characters,  proceeded 
to  place  them  in  a  separate  genus,  he  would  be  doing 
the  same  thing,  —  he  would  be  confounding  objects 
which  merely  represented  each  other  analogically,  or,  as 
it  were,  allegorically,  under  the  belief  that  they  were 
bond  fide  connected  by  affinity,  and  followed  each  other 
in  the  scale  of  nature. 

(272.)  But  if  all  this  be  admitted,  the  difficulty  of 
separating  species  from  varieties  still  remains  :  a  species, 
it  has  been  said,  is  the  only  absolute  division  in  nature ; 
and  did  we  look  to  the  vertebrated,  and  even  the  annu- 
lose,  animals,  we  might  be  tempted  to  adopt  this  as  an 
axiom  ;  but  in  regard  to  the  present  family,  at  least,  it 
cannot  be  maintained,  for  it  receives  a  direct  contradic- 
tion. The  mode  of  generation  in  the  whole  of  the 
Dithyra  precludes  the  theory  of  promiscuous  intercourse, 
and  the  consequent  production  of  hybrids.*  The  vari- 
ations, therefore,  are  spontaneous,  and  lie  beyond  our  in- 
vestigation. We  have  seen,  however,  in  the  case  of  the 
Unio  MytU'iodes,  that  while  Nature  appears  to  disregard 
all  her  usual  bounds,  and  to  indulge  in  almost  endless 
diversity,  she  nevertheless  strictly  confines  herself  to  the 
same  plan  she  has  pursued  in  all  other  groups.  Her  vari- 
ations are  upon  the  same  system  as  that  which  pervades 
the  animal  world.  She  creates,  in  short,  a  type,  all  the 
variations  of  which  have  a  reference  to,  and  often  the 
very  aspect  of,  those  particular  forms  which  mark  the 
primary  divisions  of  the  whole  family.  This  theory, 
borne  out  in  almost  every  group  here  laid  before  the 
reader,  will  materially,  if  not  absolutely,  guide  us  in 
determining  the  limits  of  species,  and  consequently  of 
varieties.  We  trust  the  rising  school  of  American  ma- 
lacologists  will  confirm  this  by  a  renewed  investigation  of 
the  inexhaustible  profusion  of  Unionidce  with  which 
their  noble  rivers  abound.     Having  seen  but  very  few  of 

*  On  all  anatomical  facts,  we  look  to  the  illustrious  Cuvier  as  a  para- 
mount authority  ;  he  expressly  says  all  the  DiUnjra  are  hermaphrodites. 
Mr.  Lea,  however,  mentions  male  and  female  shell-tish  of  the  same  spe- 
cies.    Is  there  no  error  in  this  ? 


CHAP.   X. 


BRANCHIOPODA 


•CHELYOSOMA. 


293 


the  valuable  Essays,  &c.  published  in  their  own  country  on 
the  species,  we  have  not  ventured  to  carry  our  analysis 
so  far  :  our  object  for  the  last  twenty-three  years  has 
been  to  discover  the  fundamental  principles  of  their 
natural  arrangement.  How  far  we  have  done  this,  time 
alone  will  show.  iVIuch  uncertainty,  indeed,  hangs  over 
the  location  of  one  or  two  genera ;  but  this,  however 
desirable  to  be  cleared  up,  affects  not  the  principle  itself, 
—  for  that  coincides  with  all  we  know  of  the  universal 
laws  of  animal  variation. 

(^2,73.)  Our  remaining  space  is  now  so  contracted, 
that  we  can  do  no  more  than  merely  glance  at  the  two 
remaining  tribes  of  the  Dithyra.  The  Branchiojjoda, 
indeed,  have  already  been  slightly  noticed  (238);  while 
the  annexed  cut  (Jig.  63.)  of  Mr.  Broderip's  Chelyosoma 


will  give  a  good  idea  of  this  most  extraordinary  animal. 
According  to  that  very  able  naturalist,  it  adheres  to 
stones  by  coiiacious  processes  from  the  lower  part.  It 
must  be  observed,  however,  that  on  this  lower  or  cup- 
shaped  part,  there  are  slight  traces  of  separation  into 
plates,  but  without  internal  muscular  fibre.  The  upper 
surface  is  flat,  and  consists  of  eight  coriaceous,  some- 
what horny  angular  plates,  which  are  so  disposed  that 
the  branchial  orifice  (a)  is  surrounded  by  three  plates, 
and  the  anal  orifice  (b)  by  four :  each  of  the  plates  are 
marked  by  elevated  stria?,  as  in  the  tortoises.  The  valves 
of  the  orifices  are  opened  and  closed  by  muscles,  adhering 
at  one  end  to  the  inner  surface  of  the  tunic  (not  of  the 
mantle),  and  on  the  other  to  a  small  papillary  process  on 

u  3 


£94  SHELLS    AND    SHELL-FISH.  PART  I. 

the  valves  themselves.  Besides  this  set  of  muscles^  and 
within  them,  is  another  set,  which  passes  laterally  from 
one  papilla  to  another.  Other  muscles  enable  the  ani- 
mal to  contract  or  dilate  itself.  The  ovaries,  viscera, 
&c.,  were  in  too  decayed  a  state  for  examination  ;  but 
the  mantle  appears  to  adhere  only  to  the  orifices,  each  of 
which  has  six  valves.*  Wherever  this  animal  is  placed, 
its  extraordinary  analogy  to  the  CydohraiicMa  and  the 
other  cheloniform  types,  will  still  be  the  same;  and  our 
present  impression  is,  that  it  represents  the  chitons  in 
this  division  of  the  order  rather  than  in  that  of  the  Tu- 
nicata. 

(274.)  Having  now  completed  our  exposition  of  the 
two  great  typical  divisions  of  the  Testacea,  in  which 
are  included  the  whole  of  the  univalve  and  bivalve  shell- 
fish t,  we  must  reluctantly  close  this  part  of  our  volume. 
The  whole  of  the  aberrant  orders,  as  the  Cephalopoda,  the 
Parencliymata,  and  the  Nudihranchki,  together  with  the 
radiated  and  the  coralline  MoUusks,  will  therefore  re- 
main open  to  future  investigators  of  the  natural  system, 
and  they  may  possibly  form  hereafter  the  subject  of 
another  volume  supplementary  to  this. 

*  Abridged  from  Zool.  Journal,  vol.  v.  p.  46. 

f  Excepting  those  of  the  Cephalopoda  or  Nautilus  order. 


PART  II. 

A  NATURAL  ARRANGEMENT 

OF    THE    UNIVALVE    AND     BIVALVE     SHELL-FISH,    COMPOSING 

THE    OBDICRS 

GASTEROPODA  AND  DITHYRA 

OF    THE    CLASS 

TESTACEA. 


Chief  Abbreviations. 

Bligh  Cat.     Catalogue  of  the  Bligh  Mart,  or  Mar.     Martini. 

Shells.  Sow.   Gen.  or  S.   Gen.    Sowerbi/'s 
Chem.  or  Ch.     Chemnitz.  Genera  of  Shells. 

Ency.  Meth.  or  En.  M.    Encyclo-  Sow.  Man.      Sowerby's   Manual  of 

pedie  Methodique.  Conchology. 

Lam.    System  of  Invertebrated  ani-  Tank.  C.     Tankerville  Catalog^(e. 

mats  ;  the  No.  refers  to  his  series  Zool.  111.  i.  &  ii.      Zoological   fllus- 

of  species  in  the  original  edition.  trations.  First  and  Second  Series. 


Order  GASTEROPODA. 
Tribe  ZOOPHAGA.     Carnhwous  Gastropods. 

Family  1.  MURICIDiE.     Murexes  and  Whelks. 

Pillar  never  plaited  ;  shell    spiral,   the   base  narrowed, 
and  either  truncate  or  slightly  produced. 

SuB-FAM.   1.     MURICIN^.    Murexes. 

Spire  as   long   as   the  aperture ;    exterior    rough ;    the 
whorls  marked  with  varices  ;  aperture  wide. 

MuREx  Lin.  Varices  from  three  to  five  on  each  whorl ; 

u  4 


296 


SHELLS    AND    SHELL-FISH.  PART  II. 


inner  lip  smooth  ;  the  spire  much  shorter  than  the 
aperture  ;  an  internal  groove  at  the  upper  angle  of 
the  aperture. 

Mureoc  Lin.  Canal  very  long ;  shell  armed  with  acute, 
cylindrical_,  tooth-like  spines,  mostly  arranged  in  three 
varices. 

tenuispina.  Sow.  Gen.  f.  2.  cornutus.  Mart.  114.  f.  1057. 

crassispina.    Mart.  f.  1052-4.     brandaris.    lb.  f.  1050.  1058. 

Haustellaria  Sw.  Canal  excessively  long  ;  shell  with- 
out spines  ;  the  varices  tuberculated. 

erythrostoma  Sw.    Sow.  Gen.  f.  1.  (Murex  haustellum  L. ) 

Phyllonotus  Sw.  Canal  moderate  ;  varices  foliated,  la- 
ciniated,  compressed,  or  resembling  leaves  (^fig.QQ.d). 

inflatus.      Mart.  102.  f.  980.  endeva.    lb.  107.  f.  107,108. 
eurystomus.  Zool. 111.  ii.  100.  (Aberrant.) 

imperialis.    lb.  pi.  109.  adustus.    lb.  f.  990,  991. 

cervicornis.    Sow.  Gen.  f.4.  trunculus.  lb.  f.  1018, 1019. 

Scorpio.    lb.  f.  3.  saxatilis.    lb.  f.  1011,  1012. 

ealcitrapa.  Mart.  102.  f.  982.  palmaroScE.  Lister.  946. f.  41. 

brevifrons.    lb.  f.  983.  capucinus.  Chem.  192.  1849. 
axicornis.  Mart.  105.  f.  989. 

Muricanthus  Sw.*  Varices  numerous,  foliated ;  spire 
short ;  margin  of  the  outer  lip  with  a  prominent 
tooth  near  the  base. 

radix  Siv.  Zool.  111.  2d  series,     melanomathus.      En.    Meth. 
pi.  113.  418.  f.  2. 

Pteronotus  Sw.  Varices  three,  compressed,  fin-shaped ; 
canal  moderate,  generally  closed  by  the  union  of  the 
two  lips  at  their  base. 

pinnatus.  Zool.  111.  ii.  pi.  112.  tricarinatus.  En.  INI.  418.  f.  5. 

tripteroides.  En.  M.  417.  f.  3.  phyllopterus.  Sow.  Gen.  f.  5. 

trigonularis.    Mart.  f.  1031.  gibbosus.    En.  M.  418.  f.  1. 

hemitripterus.    En.  M.  418.  acanthopterus.    lb.  417.  f.  2. 

f.  4.  uncinarius.  Mart.  f.  1034-5. 

MuRiciDEA  Sw.       Spire  more    produced,    as    long   or 


*  This  type  was  originally  called  Ccntronotus;  but  .is  that  name  had  been 
previously  given  to  a  genus  of  fishes,  we  substitute  the  above. 


PART  II. 


MURICIN^.- 


•GASSING. 


297 


longer  than  the  body  whorl ;  varices  numerous ;  no  in- 
ternal channel  at  the  top  of  the  aperture,  (^fig.  Q5.  c.) 

lamellosa.   Chem.  f.  1823-4.  scaber.     En.  Meth.  419.  f.  6. 

magellanica.  En.  M.419.  f.4.  hexagona.    lb.  418.  f.  3. 

peruviana.    lb.  f.  5.  erinacea.  Mart.  f.  1026. 
senticosa.    lb.  f.  3. 

ViTULARiA  Sw.     General  habit  of  Muricidea,  but  the 
inner  lip  is  depressed  and  flattened  as  in  the  Pur- 
purincB;  varices  simple,  nearly  obsolete  (^fig.  Q5.  e.) 
tuberculata  Sw.    En.  M.  419.   f.  1.  {Afurex  vitulinus  Auct.) 

Triton  *  Lam.  The  varices  few^  and  placed         -'^^  ^ 
alternately,     (fig.  64.) 

australis.    Sow.  Gen.  f.  1.  ^^^^^^^ 

lotorium.  lb.  f.  1.  (Jig. 66.  e)  '—  "°^ 

anus.  lb.  f.  2.    clavator.  f.  3, 
variegatum.   (Jig.  65.  d) 

Ranella  Lam.     Varices  forming  a  ridge  on 
both  sides  of  the  shell ;  channel  short. 


marginata. 
caudisata. 


Sow.  Gen.  f.  2. 
lb.  f.  1. 


spinosa.  En.  M.  421.  5- 
crumena.   lb.  421.3. 


SuB-FAM.  2.      CASSINtE. 
SheU    large,  ventricose,    generally  smooth  ;  spire  very 


*  This  is  the  only  character  by  which  this  group,  as  a  genus,  can  be  dis- 
tinguished; and  this  is  exceptionable,  because  there  are  some  species,  like 
T.clandestinuni  {fig.  Q^-),  which  have  the  outer  lip  thickened,  and  are  with- 


298 


SHELLS    AND    SHELL-FISH. 


PART  II. 


short ;    the  base    truncate   and  emarginate,   or   with  a 
short  recurved  channel ;  inner  lip  toothed  or  plaited.* 

Harpa  Lam.  Varices  numerous  and  regular^  forming 
longitudinal  ribs,  coronated  near  the  suture  ;  aperture 
and  lips  highly  polished  ;  base  truncate  {fig.  Q5.  b^c). 
muhicostata.  Sow.  Gen.  f.l.      crenata  Sw.  Bligh,  Cat. 

CypRiECASsis  Stuclibury.  Shell  oblong,  oval,  ventri- 
cose,  without  varices ;  spire  very  small ;  aperture 
cypraeiform  ;  outer  lip  thickened,  convex,  and  ad- 
vancing on  the  spire  ;  inner  margin  regularly  toothed ; 
inner  lip  thickened,  convex,  and  spreading  on  the 
body-whorl,  without  being  detached  ;  pillar  angu- 
lated  internally,  and  crossed  by  uniformly  slender 
plaits  ;  canal  very  short,  reposing  on  the  body- whorl; 
aperture  very  narrow, with  a  recurved  channel  above. 

testiculus.   Mart.  f.  375.  ?  crumena.    Mart.  37.  f.  379. 

rufa.    lb.  32.  f.  .341.  harpjBformis.  Lam.  No.  26.t 

Cassis  Lam,     Shell  ponderous,  marked  with  varices ; 


out  any  varices.  There  is,  in  fact,  every  modification  of  shape  among  the 
Tritons  as  they  now  stand  ;  some  have  the  aperture  wide,  others  narrow: 
the  channel  is  either  very  long  or  truncate  ;  the  spire  greatly  lengtliened 
or  greatly  depressed  ;  the  pillar  toothed  or  smooth  ;  the  varices  cither  alter- 
nate or none.     But,  the  suh-genera  not  having  been  determined,  I  leave 

the  group  in  this  confused  state.  These  facts,  better  than  any  theoretical 
arguments,  show  the  absolute  necessity  of  defining  the  sub-genera. 

*  Except  in  Dolium  and  Harpa. 

f  Uniting  this  genus  to  Harpa. 


PART  II.  CASSINiE. NASSINJE.  299 

outer  lip  (typically)  considerably  dilated,  with  a  pro- 
minentj  callous,  and  detached  rim  ;  inner  lip  inflected, 
broad,  flattened,  dilated  in  the  middle,  and  toothed  ; 
aperture  narrow,  irregular,  {fig.  65.  «.) 
cornuta    (type).    Chem.    pi.      flammea.En.  Meth.  406.  f.  3. 

184,  185.  (Jfiff.  65.  a.)  (Aberrant.) 

tuberosa.   Mart.  38.  f.  382.        fasclata.     Mart.  37.  f.  384. 

Cassidea  Sw.  Aperture  wide ;  outer  lip  never  broad 
or  flattened,  but  sometimes  slightly  inflected  ;  inner 
lip  spreading,  but  never  dilated  or  detached  beyond 
the  base  into  a  prominent  rim.  (fig.  66.  a.) 

glauca.    Sow.  Gen.  f.  1.  zelanica.    lb.  18. 

plicaria.    Chem.  f.  1459-60.  sulcosa.    Seba.  68.  f.  14,  15. 

areola.    En.  M,  407.  f.  3.  granulosa.     Mart.  f.  344-5. 

Zebra.    Chem.  f.  1457-8.  Saburon.    Gualt.  39.  g. 

decussata.    Mart.  f.  360-1.  semigranosa.    Lam.  No.  23. 

ringens  Sw.   Bligh,  Cat.  vibex.   Mart.  35.  f.  364-6. 

achatina.  En.  Meth.  407.  f.  1.  erinaceus.    lb.  35.  fig.  363. 
pyrmn.    Lam.  No.  17. 

DoLiUM  Lam.     Shell  ventricose,  inflated,  smooth  ;  spire 
very  short ;  outer  lip  thin,  not  inflected ;  base  ge- 
nerally truncate  and  emarginate.  {fig.  66.  6.) 
D.    olearium.     Sow,  Gen.  f.  1.      fimbriatum.    lb.  f.  2. 

SuB-FAM.  3.    NASSINiE. 

Generally  small ;  the  spire  longer  than  the  aperture  * ; 
the  base  either  truncate,  or  with  a  short  recurved 
channel ;  inner  lip  often  dilated  and  spreading  ;  some- 
times granulated,  but  never  toothed  ;  a  prominent  ridge 
or  fold  at  the  base  of  the  pillar;  outer  lip  crenated  within. 

Cassidarea  Zflw.    Ventricose;  spire  short;  inner  lip 
spreading,  and  detached  at  the  base ;  outer  lip  thick- 
ened within  ;  canal  slightly  lengthened,  and  turning 
upwards  ;  representing  Cassis. 
echinophora.  Ency.  M.  405.  f.  3.      Thyrrena.  lb.  405.  f.  1. 

Oniscidia  Sow.     General  shape  of  Cyprcecassis,  but  less 
ventricose,  the  base  more  attenuated,  and  the  canal 

*  But  in  the  aberrant  genera  it  is  shorter. 


300 


SHELLS    AND    SHELL-FISH. 


PART   II. 


truncated ;    spire  very   short ;    both  lips  thickened^ 
the  inner  granulated,  the  outer  inflected  and  toothed  ; 
aperture  narrow,  (^fig.  QQ.  c.) 
oniscus.    Chem.  1872-3.  cancellata.  Sow.  Gen.  f.  1 — 3. 

Vexilla  Sw.     General  shape  of       ^  ^^ 

Purpura  ;  the  inner  lip  flat- 
tened and  depressed;  the  outer, 
when  adult,  thickened,  in- 
flectedj  and  toothed ;  aperture 
wide. 

picta  Sw.   Chem.  pi.  157.  f.  1504-5.  {fig.  61.) 

Nassa  Layji.     Small  ;  spire  longer  than   the 

aperture  ;    the    inner    lip,    in    the    typical 

forms,  greatly  dilated,  thickened,  and  often 

with  a  prominent  margin  ;  outer  lip  simple, 

crenated ;  aperture  wide,  with  a  groove  above ; 

pillar  with  a  basal  ridge;  base  truncate,    {fig.  68.) 

N.   arcularia.    Ency.  M.  394.  f.  1.      clathrata.     lb.  f.  4. 
papillosa.     Sow.  Gen.  f.  5. 

Cyclonassa*  Sw.  Shell  small,  depressed,  neritiform, 
nearly  round ;  inner  lip  forming  a  vitreous,  spreading 
mass  ;  no  internal  canal  or  tubercle  on  the  inner 
lip ;  basal  notch  nearly  obsolete  ;  outer  lip  smooth, 
entire,  thickened. 

C.  neritea.     Ency.  M.  394.  f.  9.      Sow.  Gen.  f.  3. 

SuB-FAM.  4.     PURPURIN^. 
Oval;  spire  much  shorter  than  the  aperture,  which  is  very 
wide  ;  inner  lip  not  defined,  but  vitreous  ;  pillar  broad 
and  flattened  ;  outer  lip  rarely  thickened  or  inflexed, 

RiciNULA  Lam.  {fig.  71.  rf.)  Outer  lip  dilated,  and  often 

forming  digitated  processes  externally,  but  the  margin 

broad,  much  reflected,  and  toothed  internally  ;  inner 

lip  flat,  broad,  generally  toothed  ;  spire  very  small.  \ 

planospira.  En.  M.  397.5.        digitata.    Sow.  Gen.  f.  3,  4. 
horrida.    Sow.  Gen.  f,  1.  morus.    lb.  f.  2. 

*  The  fanciful  and  inapplicable  name  of  Cyclops,  given  to  this  type  by 
De  Moiitford,  designates  a  well-known  genus  of  Crustacea. 
+  Except  in  those  species,  like  R.  ■»iunis,  which  lead  to  Purpura. 


PART  II. 


PURPURIN^. 


•BUGGING. 


301 


CoNCHOLEPAS  Lam.     Patelliform ;   spire  lateral,  nearly- 
obsolete ;  pillar  none. 

C.  Peruviana.     Sow.   Gen.   {fig-  71.  a.) 

MoNCGEROs  Lam.     Spire  moderate ;    a 

strong  tooth-like  process^at  the  base  of 

the  outer  lip.  (^fig.  6^. ) 

M.  imbricatum.    Sow.  Gen.  f.  1. 
cinffulatum.  lb.  fisr.  4. 


MicROTOJiA  Sw.  Pillar  very  broad  and 
curving  inwards  ;  aperture  effuse ; 
the  notch  at  the  base  small^  and  nearly- 
obsolete  ;  spire  very  short. 

patula.  Mart.  69.  f.  758,  759.     persica.  En.  Meth.  397.  f.  1. 

unicolor  5'u\      Cheni.  f.  1449. 

Purpura  Lam.  Spire  more  prominent ; 
inner  lip  flattened ;  the  basal  notch 
wide  and  distinct.*  {fig-  10,  11.  h.) 

coronata.  En.  Meth.  397.  f.  1. 
succincta.    lb.  398.  f.  1. 


SuB-FAM.  5.    BUCCININ.E. 
Spire  always  as  long  as  the  aperture,  and 


»  United  to  Ricinula  by  P.  columellaris.,  Ency.  Meth.  598.  fig.  3.,  and 
Ricinuia  morus,  Ency.  Meth.  395.  fig.  6. 


302  SHELLS    AND    SHELL-FISH.  PART  II. 

typically  of  great  length ;  base  truncated,  deeply  notched; 
inner  lip  smooth,  convex. 

Leiodomus  Sw.  Shell  very  smooth,  nearly  polished  ; 
spire  acute,  slender,  lengthened;  of  few  whorls; 
aperture  effuse;  inner  lip  thickened  and  spreading; 
base  of  the  pillar  curving  inwards.    8  species. 

Achatinum.  En.  M.  400.  f.4.      Quoyii^w;.     Voy.  d'Astrol. 
vittata.  En.  Meth.  402.  f.  4.  31.  f.  17. 

Terebba  Lam.*      Shell   subulate;    spire   excessively 
long,  and  of  numerous  whorls ;  pillar  straight ;  the 
base  curving  outwards  {Jig.  71.  e). 
maculata.    En.  M.  402.  f.  4.      Babylonica.   lb.  402.  f.  5. 

BucciNvisi  Linn.  Shell  pyriform ;  spine  moderate;  body- 
whorl  ventricose ;  base  obtuse,  emarginate ;  hps 
smooth  {fig.  11.  c). 

undatum.  En.  M.  399.  f.  1.       lineatum.  lb.  400.  f.  8. 
?  leevigatum.   lb.  400.  f.  1 .  t      papillosum.   lb.  400.  f.  2. 

Trochia  Sw.     Shape  intermediate  between  Purpura 
and  Bucciniim  ;  whorls  separated  by  a  deep  groove  ; 
inner  lip,  when  young,  depressed,   when  adult,  thick- 
ened, convex,  and  striated  ;   basal  canal  very  small, 
sulcata.    En.  M^th.  422.  f.  4. 

Tritonidea  X  Sw.  Shell  bucciniform,  but  the  basal  half 
is  narrowed,  and  the  middle  more  or  less  ventricose  ; 
spire  and  aperture  equal.  Pillar  at  the  base  with 
two  or  three  obtuse  and  very  transverse  plaits,  not 
well  defined ;    outer  lip  internally  crenated,  and  with 

*  By  this  group,  the  Muricid^  are  connected  with  the  Strombid^  by 
means  of  the  Ccriiliince. 

t  Probably  an  aberrant  species  of  Leiodomus. 

%  Mr.  Gray  has  the  merit  of  first  publishing  this  intricate,  but  most  natu- 
ral genus,  which  I  had  many  years  ago  also  determined.  1  should  gladly 
have  adopted  his  name,  were  it  not  that  Pollia  has  been  already  given  by 
Hiihner  and  Trcitsch  to  a  genus  of  lepidopterous  insects.  Mr.  Gray  has  very 
happily  determined  what  is  certainly  its  true  station  in  the  natural  system, 
—  that  is,  intermediate  between  Triton  and  Biiccinmn.  It  is  connected  to 
rritun  by  T.  clandcsfinum.  Ency.  Meth.  433.  fig.  1.  [Jig.  C4.  p.  297.),  which 
thus  completes  the  circle  of  this  family. 


PART  II. 


TURBINELLID^. 


303 


a    superior    siphon ;    inner    lip    wanting,    or    rudi- 
mentary. 

undosa.  En.  M^th,  422.  f.  5.  (Aberrant.) 


torulosa.    lb.  428.  f.  3. 
maculosa.   lb.  400.  f.  7. 


aculeiformis.    lb.  426.  f.  3. 
articulata.  En.  M.  426.  f.  1. 


Family  2.     TURBINELLIDiE. 

Base  of  the  shell  produced  into  along  channel ;  the  spire 
generally  short ;  the  pillar  often  toothed  ;  outer  lip  thin. 


SuB-FAM.  1.     TURBINELLIN^. 

Spire  short,  the   tip   papillary  ;  middle  or  base  of  the 
inner  lip  plaited ;   channel  lengthened. 

TuRBiNELLA  Lum.  Shell  ponderous,  smooth,  or 
slightly  nodulous ;  spire  short,  papillary  ;  pillar  with 
strong  plaits  in  the  middle,  (^fig.  72.  a.) 

rapa.  En.  Meth.  431.62s,  f.  1.      pyrum.  Chem.  f.  1697,  1698. 

Fasciolaria  Lam.  Fusiform,  ventricose ;  spire  and 
aperture  of  equal  length,  the  former  attenuated  and 


304}  SHELLS    AND    SHELL-FISH.  PART  II. 

acute  ;  outer  lip  crenated  ;  base  of  the  pillar  with 
one  or  two  sharp  folds.  {Jig.  72.  d.) 
F.  tulipa.  En.Meth.  431.  f.  2.     trapezium.     lb.  431.  f.  3. 

Pyrella  Sw.  Pyriform  ;  spire  very  shorty  papillary  ; 
channel  lengthened;  inner  lip  flattened,  elevated^ 
smooth  ;  pillar  with  a  single  sharp  fold  at  the  base. 

P.  spirilla.     Zool.  111.  1st  series.      En.  Meth.  437.  f.  4. 

Clavilithes  Sw.  Unequally  fusiform,  the  body-whorl 
and  spire  being  conic,  and  the  canal  suddenly  con- 
tracted and  attenuated  ;  terminal  whorls  papillary  ; 
inner  lip  thick;  pillar  smooth.  Fossil  only.  {Jig.  72.  b.) 

longfevus.    En.  M.  425.  f.  3.        Noa?.     En.  Meth.  425.  f.  5. 
clavellatus.      lb.  f.  2.  ponderosus  Sw.     lb.  f.  4. 


SuB-FAM.  2.      SCOLYMIN^. 

Spire    more  produced,    the  tip  always   acute;    surface 
rough  ;   canal  short ;  pillar  plaited. 

Plicatella*  Sw.  Fusiform  ;  the  spire  produced  ;  pil- 
lar with  two  or  three  obtuse,  basal,  transverse  folds. 

polyzona.   En.  M.  423.  f.  1.  rustica.      Mart.  120.  f.  1104. 

cingulifera.   lb.  429.  f.  1.  triserialis.       Lam.     No.   21. 

earinifera.    lb.  423.  f.  3.  ocellata.    Mart.  124.  f.  1 160. 

infundibulum.    lb.  424.  f.  2.  variolosa.      Lam.  No.  22. 

craticulata.   lb.  429.  f.  3.  tuberculata.  Grif.Cuv.30.f.3. 

lineata.   lb.  429.  f.  4.  turbinelloides.      lb.  25.  f.  1. 

nassatula.   Lam.  No.  20.  filosa.      En.  Meth.  429.  f.  5. 

ScoLYMus  Sw.  Sub-fusiform,  armed  with  foliated 
spires  ;  spire  shorter  ;  pillar  with  distinct  plaits  in 
the  middle. 

cornigerus.  Chem.  f.  1725-6.  capitellum.     En.  Meth.  431. 
pugellaris.  En.M.401.  6is*,3.  bis  *,  f.  4. 

globulus.     lb.  f,  2.  umbilicaris.      lb.  f.  1.  a — c. 

rhinoceros.  Chem.  f.  1407-8.  mitis.     Lam.  No.  10.  p.  106. 
ceramica.     Mart.  99.  f.  943. 


*  rolygonum  of  some  writers;    but  that  is  a  common  and  well-known 
botanical  genus  of  Linnaeus,  and  cannot  thereiore  be  again  applied. 


PART  II.  SCOLYMIN^. EBURNIN^.  305 

Cancellaria  Lam.  Shell  turbinate,  scabrous,  generally 
reticulated  ;  body-whorl  ventricose  ;  spire  and  aper- 
ture nearly  equal ;  base  obtuse  ;  pillar  with  distinct 
basal  plaits  ;  aperture  rather  eflPuse  j  the  canal  almost 
obsolete. 
C.  reticulata.  En.  Meth.  375.  f.  3.     lobata  Sw.  (Jig.  72.  /. ) 

Rhinodomus  Sw.  No  internal  groove  ;  shell  clavate ; 
the  spire  longer  than,  or  equal  with,  the  aperture  ;  the 
whorls  with  ridges  or  longitudinal  varices,  and  ren- 
dered hispid  by  transverse  grooves ;  inner  lip  want- 
ing ;  pillar  with  a  terminal  fold ;  aperture  striated  ; 
outer  lip  with  a  basal  sinus.* 

R.  senticosus.      Chem,  tab.  193.  f.  1864—1866. 

PoLYTROPA  Sw.  "j"  Bucciniform  ;  but  the  base  narrowed, 
and  ending  in  a  straight  and  contracted,  but  rather 
short,  channel ;  spire  longer  or  as  long  as  the  aper- 
ture ;  exterior  folliculated  or  tuberculated  ;  inner  lip 
flattened,  as  in  Purpura;  basal  notch  small,  oblique  ; 
no  internal  channel. 

crispata.    En.  Meth.  41 9  f.  2.      imbricata.  Mart.  1 22.  f.  1 1 24. 

Chem.  187.  f.  1802.  ?  ruj?osa.    Chem.  f.  1473-4. 

lapilla.  Pennant,  pi.  72.  f.  89. 


'o^ 


SuB-FAM.   3.     EBURNIN^. 

Shell  generally  grooved  round  the  suture  ;  body-whorl 
ventricose  ;  spire  rather  longer  than  the  aperture ;  the 
base  obtuse,  and  almost  entire ;  inner  lip  much  thick- 
ened ;  outer  lip  sinuated. 

Cyllene  Gray.     Small;  shape  of  Harpa  and  Harpula; 
shell  longitudinally  ribbed^  and  sub-coronated  with 

*  Analogous  to  Nassa;  but  the  inner  lip  is  not  developed,  and  there  is  not 
a  superior  or  internal  canal ;  it  likewise  represents  Leiodo??ius  by  its  animal, 
Scalaria  by  its  varices,  and  Terebra  by  it  spire.  There  are  several  species 
with  shorter  spires  than  senticosus. 

t  This  is  an  obvious  representationof  P?/rjDwra  and  Fyrula  in  this  circle, 
and  is  connected  to  Plicatella  by  such  aberrant  species  as  have  two  or  three 
obsolete  tubercles  at  the  base  of  the  inner  lip,  and  a  row  of  others,  more 
distinct,  on  the  opposite  side  ;  but  even  in  these  the  pillar  is  always  de- 
pressed, and  the  channel  short.  These  species  are  chiefly  from  the  Northern 
and  Southern  Oceans.  They  are  at  once  distinguished  from  the  FurjmrcE 
by  having  no  internal  channel  at  the  top  of  the  aperture, 

X 


306 


SHELLS    AND    SHELL-FISH.  PART  11. 


tubercles,  sometimes  cancellated ;  aperture  striated 
within,  rather  effuse,  longer  than  the  spire,  which  is 
acute ;  inner  lip  large,  vitreous,  spreading ;  the  base 
finely  striated ;  outer  lip  with  a  slight  sinus  at  the 
base,  as  in  Rhinodomus ;  no  internal  groove ;  the 
suture  sometimes  channeled  and  polished. 
C.  Owenii.    GrifF.  Cuv.  p.  41.  f.  2. 

Struthiolaria  Lam.     Spire  turreted ;  outer  lip  con- 
siderably sinuated ;  inner  lip   thick,  spreading ;  the 
pillar  turned  inwards  ;  the  basal  notch    nearly  obso- 
lete, 
nodulosa.  En.  M.  431.  f.  1.     crenulata.  Astrol.  pi.  31. f.  8,9. 

Eburna  Lam.      Smooth;  sutures   gene-  ,«^^  '^ 

rally  grooved  ;  spire  and  aperture  about 
equal ;  inner  lip  very  thick,  partly  con- 
cealing the  umbilicus,  and  with  an  up- 
per internal  groove ;  outer  lip  thin, 
slightly  sinuated  ;  basal  notch  oblique, 
small,  {jig.  73.) 

E.spirata.  En.Meth.401.f.2.      pacifica.    En.  Moth.  401.  f. 4. 

PsEUDOLivA  Sw.  Shell  thick,  oval,  oliviform,  ventricose; 
spire  very  short,  acute ;  base  with  two  parallel 
grooves,  one  of  which  forms  a  notch  at  the  base  of 
the  outer  lip  ;  suture  slightly  channeled  ;  inner  lip 
very  thick,  and  turning  inwards  ;  aperture  with  an 
internal  canal.  Connects  the  Turbinellid^  with 
the  VoLUTiD^. 
P.  plumbea.     Chem.  188.  f.  1806,  1807.  {fig.  5.  p.  82.) 

Latiaxis  Sw.  Shell  sub-pyriform,  turbinate,  and 
the  whorls  detached,  as  if  distorted  ;  but  the  spire 
flattened  at  the  summit ;  whorls  angiJated,  and  cari- 
nated,  with  a  fimbriated  undulate  ridge  ;  pillar  none  ; 
umbilicus  excessively  large  and  deep  ;  aperture  an- 
gular ;  the  basal  notch  nearly  obsolete.* 
P.  Mawcx.      Grift:  Cuv.  pi.  25.  f.  4. 

*  This  singular  shell  I  regard  as  the  representation  of  Scalnria,  Verme- 
ius,  &c.  in  the  present  group,  and  as  opening  a  passage  to  the  Pyruliua  by 


PART   II. 


PYRULINiE.  S07 


SUB-FAM.   4.       PYRULINiE. 

Shell  pyriform  ;  the  base  more  or  less  produced ;  the 
spire  short  and  typically  flattened ;  inner  lip  convex, 
and  perfectly  smooth.  *  ' 

Rapella  Sw.  Shell  ventricose,  generally  thin,  almost 
globose  ;  the  base  suddenly  contracted,  and  forming 
a  short  canal,  the  channel  almost  obsolete ;  umbilicus 
large,  partly  concealed  by  the  inner  lip. 

R.  papyracia.      En.  Meth.  436.  f.  1. 

FicuLA  Sw.     Shell  thin,   pyriform  ;    the 

base     lengthened    into    an     elongated 

channel ;    the   upper  part  ventricose ; 

spire  very  small,   depressed ;   inner  lip 

wanting,    {^fig.  74.) 

ficus.  En.  M6th.431.      caudata.     En.  Meth. 
f.  1.  436.f.l.6,c. 

Pyrula  Lam.     Shell  strong,   pyriform, 

solid,    coronated  wiih   spines  or  tubercles ;   the  base 

lengthened  into  a  long  channel ;  spire   very    short, 

but  a  little  elevated  and  pointed ;  inner  lip  wanting. 
P.  perversa.     En.  Meth.  433.  f.  4. 

CuMA    Humphrey.      Sub-fusiform  ;     spire     and    base 
equal  in  length ;  inner  lip  with  a  central  fold. 
C.  sulcata  Sw.      (See  Jig.  4.  p.  87.) 

Myristica  Sw.  Sub-pyriform  ;  spire  strong,  spiny, 
or  tuber culated,  nearly  as  long  as  the  base  ;  um- 
bilicus either  partially  or  entirely  concealed ;  inner 
lip  vitreous,  thin ;  the  outer  with  an  internal  and 
ascending  canal ;  the  basal  channel  wide. 

hippocastanea.    En.  M.  432.     melongena.    En.  Meth.  435. 

f.  4.  f.  3. 

lineata.      lb.  f.  5.  nodosa.    Chem.  1 564-5. 


means  of  Rapella.  I  know  it,  however,  only  from  the  figures  above  quoted. 
Mr.  Gray's  description  is  confined  to  these  words:  "  Shell  deformed,  white  j 
from  China."  It  is  obviously  related  to  Rapella  ;  while,  in  its  large  umbili- 
cus and  nearly  obsolete  notch,  it  has  a  greater  resemblance  to  Eburna  than 
to  any  other  genus  I  am  acquainted  with. 
*  Except  in  Cuma,  where  there  is  a  central  fold. 

X  2 


308 


SHELLS    AND    SHELL-FISH. 


lART  II. 


SuB-FAM.   5.      FUSl'N IE.  — Spindle- Shells. 

Shells  generally  fusiform  and  slender  ;  the  base  elon- 
gated ;  the  spire  lengthened  and  acute  ;  pillar  smooth  ; 
outer  lip  thin. 

Hemifusus  Sw.  Unequally  fusiform^  the  spire  being 
shorter  than  the  aperture  ;  shell  ponderous^  coronated 
with  compressed  spines ;  an  internal  and  ascending 
canal  at  the  top  of  the  aperture. 

colossus.  En.  M^th.  427.  f.  2.     morio.    En.  M^th.  430.  f.3,4. 
pyrulaceus.     lb.  429.  f.  6.  carnaria.      lb.  434.  f.  3. 

coronatus.      lb.  430.  f.  2.  cochlidium.      lb.  434.  f.  2. 

Chrysodomus  Sw.  Bucciniform,  but  the  base  pro- 
duced into  a  channel  shorter  than  the  spire ;  whorls 
ventricose ;  smooth_,  or  nearly  so ;  outer  lip  thin  ; 
inner  lip  obsolete. 

dispectus.  Ency.  M.  26.  f.  4.      sulcatus.  En.  Meth.  424.  f.  3. 
argyrostomus.  Ib.426.f.5.  lignarius.    lb.  424.  f.  6. 

Fusus  Lam,  Shell  long,  slender  ;  both  extremities 
much  produced :  spire  attenuated,  turreted,  and  of 
nearly  equal  length  with  the  aperture. 

Syracusanus.  En.  M.423.  f.6.     tuberculatus.  En.  M.  423.f.'4. 
torulosus.    lb.  f.  4.  aciculatus.    lb.  425.  f.  8. 

incrassatus.    lb.  5.  longicauda.  lb.  423.  f.  2. 

Leiostoma  Sw.  Equally  fusiform,  but  ventricose  in  the 
middle ;  shell  entirely  smooth,  almost  polished  ;  in- 
ner lip  thickened  and  vitreous  ;  base 
of  the  pillar  very  straight.  Fossil 
only.  (fig.  75.) 
L.  bulbiformis.    En.  Meth.  428.  f.  1. 

Strepsidura  Sw.  Equally  fusiform, 
but  the  basal  portion  of  the  pillar 
turned  outAvardly,  with  a  sharp  fold 
at  the  base  of  the  aperture  ;  shell 
costated  and  sub-coronated  ;  body- 
whorl  ventricose.  Fossil  only. 
S.  costata.    Sw.  En.  Meth.  428.  f.  2.  (Fusus ^culneus  ham.) 


PART  II. 


STROMBIN^. 


309 


Family  3.  STROMBID^.    Wing-Shells. 

Outer  lip  dilated^  or  thickened  internally^,  or  detached 
from  the  preceding  whorl  by  a  sinus ;  operculum  small. 

SuBFAM.  1.   STROMBIN^. 

Outer  lip  considerably  dilated,  but  never  toothed ;  spire 
rarely  longer  than  the  aperture,  with  a  sinus  near  the 
base. 

Aphorrais  Da  Co5^a.   (fig.'jG,  a.)     Spire,  longer  than 

76 


the  aperture ;  outer  lip  dilated  into  finger- like  pro- 
cesses ;    base  produced,  compressed,  with  a  slender 
grooved  channel  in  the  middle,  but  no  distinct  lobe, 
A.  pes-pelicani.   Mart,  85.  f.  848 — 850. 

Pteroceras  Lafn.  (fig.  'J'J.)  Spire 
short ;  outer  lip  considerably  di- 
lated, ascending  and  attached  to  the 
spire,  in  general  divided  into  linear 
processes ;  basal  lobe  inflexed, 
toothed ;  channel  long. 

P.  truncatus.  Chem.     latissimus         Sw. 

Mart.     83.     f. 
835. 
purpuratus       5*?^;. 
Chem.  157.      f. 
1494,  1495. 
X  3 


pl.  159. 
laciniatus.      Ex. 
Conch.        46. 
Chem.  158.  f. 
1506,  1507. 


.'^lO 


SHELLS    AND    SHELL -FISH. 


PART  II. 


Strombus  Linn.  (^fig.  76.  b)  Outer  lip  entire ;  the  mar- 
gin not  inflected,  with  a  deep  sinus  near  the  base,  and 
the  upper  part  not  ascending  to  the  top  of  the  spire ; 
basal  lobe  rarely  inflexed,  and  never  toothed. 

tricornis.  En.  Meth.  401.  f.  1. 
Gallus.    Mart.  f.  841,  842. 
Goliathus.     Chem.  195.  B. 
inermis   Sw.    Bligh,  Cat. 
gigas.    Mart.  80.  f.  824. 
accipitrinus.     lb.  81.  f.  829. 


Pacificus  Sw.  Chem.  f.  1485, 
I486.    Ex.  Conch,  pi.  17. 

melanostomus  Sw.  lb.  f. 
1487-8.    lb.  pi.  17. 

Auris- Dianae.  Mart.  f.  838-9. 

Lamarckii.    Gray  ? 


Strombidea  Sw.  Outer  lip  angulated,  but  not  dilated, 
or  detached  from  the  preceding  whorl ;  upper  sinus 
obsolete,  or  entirely  wanting ;  the  lower  distinct. 

urceus.  Mart.  78.  f.  803.  tridentata.     Chem.  f.  1503. 

plicata.   En.  M.  408.  f.  2.  erythrostoma.     lb.  f.  1874. 

mutabilis.   Mart.  78.  f.  807.      dubia  S'w.  P.  Mag.61.  p.377. 

RosTELLARiA   Lam.    [fig.  76.  c,  d,  e.)     An    ascending 
siphon,  formed  by  a  groove  thickened  on  each  side, 
which  extends   upwards   on    the    spire  ;     outer    lip 
various,  but  not  sinuated  at  the  base, 
curvirostris.   En.  Meth.  411.      columbata.     En.  Meth.  411. 


f.l.(Jig.76.c.) 
rectirostris.  Nat.  G.  pi.  2.  f.2. 
serrata    Sw.    Chem.  195.  A. 

f.  1869. 
macroptera.     Brander,  f.  76. 


f.  2.  (Jig.  76.  c.) 
fissurella.  lb.  f,  3.  (Jig.  76.  d. ) 
cancellata.    lb.  408.  f.  5. 
canalis.    lb.  409.  f.  4. 
decussata.    Sow.  Gen.  f.  8. 


SuB-FAM.  2.    CONINiE.    Cones. 

Shell  coniform;  the  spire  very  short, 
pyramidical  or  truncate ;  outer  lip 
slightly  detached  above,  but  without 
a  basal  sinus. 

Terebellum  Lam.  Cylindrical, 
smooth ;  aperture  effuse  at  the 
base ;  outer  lip  with  an  obsolete 
sinus ;  spire  either  short  or  con- 
cealed. 

T.    subulatum.    En.  Meth.  360.  fig.  1 
(Jig.  78.) 


PART  II. 


CONINA;. 


311 


CoRONAxis  Sw.  Shell  conical ;  the  summits  of  the 
whorls  crowned  with  a  single  row  of  tubercles  ;  mouth 
of  the  animal  entire. 

Coronaxis  Sw.    Spire  truncate^  scarcely  raised  above  the 
margin  of  the  body-whorl,  which  is  not  convex. 
Bandanus  Lam.  Voy.  d'  Astrol.  pi.  53.  f.  7. 

Puncticulis  Sw.  Spire  slightly  elevated  ;  body-whorl 
convex  near  the  upper  margin ;  aperture  linear ; 
base  deeply  notched. 

P.  arenatus  Lam.     Voy.  d' Astrol.  pi.  52.  f.  8. 

TaUparia    Sw.    Body- whorl   ventricose  j    the   aperture 
effuse, 
nebulosa  Siv.      Ency.  M.  322.  f.  11.      (Conus  tulipa  L.) 

CylindreUa  Sw.  Conic-cylindrical;  spire  elevated_,  and 
only  slightly  coronated  on  the  upper  whorls  j  shell 
generally  grooved. 

Asper.      Chem.  181.  f.  1745-7. 

ConUithes  Sw.  Conic;  spire  considerably  elevated;  the 
aperture  linear. 

C.  antediluvianiis.      Sow.  Gen.  f.  1. 

CoNus  Linn.  Shell  conic ;  the  summit  of  the  whorls 
smooth ;  mouth  of  the  animal  laciniated. 

Conus  Linn.     Spire  generally  truncate,  or  only  pointed 
at   the  summit ;  margin  of  the  body- 
whorl  carinate. 

C.  millepunctatus.    En.  Meth.  323.  f.  5. 
litteratus.      lb.  323.   f.  1.  {Jig.  79.) 
eburneus.      lb.  324.   f.  1,2. 
nobilis.      lb.  339.  f.  7. 
virgo.      lb.  326.  f.  5. 
miles.      lb.  329.  f.  7. 
capitaneus.      lb.  327.  f.  2. 
vulpinus.      lb.  326.  f.  6. 
maldivus.      lb.  325.  f.  6. 
generalis.      lb.  325.  f.  2.  4. 
monile.      Chem.  140.  f.  1301 — 1303. 

Dendroconiis  Sw.    Shell  heavy ;   spire   lightly  elevated  ; 

X    4 


312  SHELLS    AND    SHELL-FISH.  PART  II. 

body  whorl    convex    near    the    margin ;     aperture 
linear. 

betulinus.     En.   Meth.   338.  franciscanus.  E.  M.  337.  f.  5. 

f.  7.  striatus.      lb.  S40.  f.  1. 

figulinus.    lb.  332.  f.  2.  gubernator.      lb.  340.  f.  5. 

quercinus.    lb.  332.  f.  6.  nimbosus.      lb.  341.  f.  5. 

Teoctilia  Sw.       Spire    elevated,    concave ;    body-whorl 

ventricose ;    the    aperture  effuse  at   the  base  ;    shell 

always  smooth. 

communis.     En.    M.  346.  f.  ammlralis.  E.  M.325.  f.  1 — 9. 

1 — 5.  bullatus.  Chem.  f.  1315 — 6. 

auratus.      lb.  343.  f.  1.  pyramidalis.  En.  Meth.  347. 
rubiginosus.  lb.  344.  f.  1,2.  f.  5. 

Theliconus  Sw.     Shell  narrow,  nearly  cylindrical,  gene- 
rally  grooved    transversely ;     spire    elevated,    thick, 
convex,  obtuse  ;  aperture  linear, 
nussatella.  Sow,  Gen.  f.  7.       Terebra.    Sow.  Gen.  f.  6. 

Leptoconus  Sw.     Shell  light,  conic,  sometimes  striated  ; 

spire  elevated,   acute,  concave ;  the  basal  whorl  cari- 

nated,  detached,  and  sinuated  above,  and  contracted 

near  the  suture. 

grandis.     Sow.    Gen.  f.  2.  duplicatus.     Sow.  Gen.  f,  5. 

amadis.    Chem.  f.  1322-3.  Austrabs.      lb.  f.  4.* 

CoNELLA  Sw.  Shell  small,  conic;  spire  elevated,  smooth; 
the  outer  lip  advancing  a  little  up  the  spire ;  aperture 
linear ;  inner  lip  smooth ;  outer  lip  striated  within, 
picata  Sw.  {fig.  17,  a,  p.  151.) 

CoNORBis  Sw.  Conic,  but  resembling  a  Pleurotoma  : 
spire  conic,  considerably  elevated;  outer  lip  with  a 
deep  sinus  above. 

C,  Dormiter,      Sow.  Gen.  f.  8. 

SuB-FAM.  3.     COLUMBELLIN^, 

Shell  small ;  outer  lip  considerably  thickened  within, 
where  the  margin  is  invariably  either  toothed  or  striated  ; 
the  top  gibbous,  the  margin  generally  in  flexed ;  inner 

*  Passing  into  Nussatdla. 


PART  II.  COLUJIBELLIN^.  313 

lip  doubly    toothed^    i.  e.  internally    and    externally ; 
aperture  narrow,  generally  ringent ;  operculum  minute. 

CoNiDEA  Sw.  Mitra-shaped,  fusiform  ;  spire  equal  or 
longer  than  the  aperture;  the  whorls  tumid  ;  outer 
lip  slightly  gibbous  above,  contracted  below ;  margin 
not  inflected  ;  striated  within  ;  inner  lip  terminating 
in  an  elevated  ridge,  but  with  the  teeth  obsolete. 

C.  semipunctata.  (Columhella  Lam.)     Mart.  44.  f.  465,466. 

CoLUMBELLA  Lum.  Subfusiform  ;  spire  shorter  than 
the  aperture ;  outer  lip  gibbous,  inflected,  sinuated, 
broad,  and  thickest  in  the  middle,  crenated  or  toothed 
its  entire  length  ;  aperture  contracted ;  inner  lip  with 
granular  teeth. 

C.  mercatoria.      Mart.  pi.  44.  452 — 458. 

PusiosTOMA  Sw.  General  form  of  Columhella  ;  but  the 
outer  lip  is  only  toothed  in  the  middle,  where  it  is 
greatly  thickened  ;  inner  lip  convex  between  the  gra- 
nular teeth,     (fg,  72.  g,  h.) 

punctata.    En.  M.  374.  f.  4.     fulgurans.      Lam.* 
mendicaria.    lb.  375.  f.  10.       turturina.   En.  M.  384.  f.  2. 

Crassispira  Sw.  Small,  subclavate,  tuberculated  :  spire 
thick,  lengthened ;  outer  lip  with  a  slight  sinus 
above,  and  thickened  internally  at  the  top  and  bottom ; 
top  of  the  inner  lip  with  a  thick  pad ;  basal  channel 
but  slightly  defined,    (fig.  17.  a.) 

Pleurotoma  Bottas  Auct.      C.  fasciata  Sw.  {fig.  17.  d,  p.  151.) 

NiTiDELLA  Sw.  Bucciniform ;  small,  ovate,  smooth, 
glassy  ;  aperture  effuse  ;  outer  lip  slightly  thickened, 
faintly  inflexed,  and  generally  striated  internally  ; 
inner  lip  somewhat  flattened  above  ;  base  of  the  pillar 
with  one  or  two  slight  internal  folds,  or  a  single  an- 
gular projection,    (fig.  17-  e.) 

Columbella  nitida  Lam.  (fig. 17.  c,  p.  151.) 

*  Lamarck  erroneously  cites  the  Ency.  Meth.  574.  fig.  7.  for  this  species, 
as  that  represents  one  of  his  Mitres. 


314  SHELLS    AND    SHELL-FISH.  PART  II. 


SuB-FAM.  4.     PLEUROTOMINiE. 

Shell  turreted,  subfusiform  ;  the  base  channeled,  and 
often  much  produced  ;  outer  lip  never  thickened,  but 
detached  at  the  top  from  the  whorl  by  a  slit  or  sinus.* 

Brachytoma  "f  Sw.  Subfusiform  ;  resembling  a  small 
Stromhus  or  Fusus ;  spire  and  aperture  of  equal 
length ;  channel  short ;  outer  lip  slightly  ascending, 
and  forming  a  short  canal ;  sinus  very  small,  and 
nearly  semi-circular ;  inner  lip  thickened  above. 

strombiformis.   Sow.    Man.     castanea  Sw.     Chem.  f.  1831, 
f.  381.  14S2. 

Pleurotoma  Lam.  Fusiform,  turreted ;  channel 
lengthened,  and  nearly  as  long  as  the  spire ;  the  slit 
long  and  narrow  ;   inner  lip  wanting. 

P.    virgo.      En.    Meth.    439.       Babylonica.      lb.  f.  1. 
f.  2.  ^  Javanica.      lb.  f.  3. 

Clavatula  Sw.  Spire  clavate,  very  long,  turreted ; 
channel  short ;  inner  lip  wanting. 

sulcata  Sw.     Chem.  190.  f.  1829. 

Clavicantha  Sw.  Thick,  sub-fusiform  ;  the  surface 
rugose,  and  the  whorls  sub-coronated  ;  channel  short ; 
slit  assuming  the  form  of  a  short  broad  sinus. 

C.  imperialis.      En.    Meth.      conica.      E.  M.  439.  f.  9. 
440.  echinata.      lb.  439.  f.  8. 

spirata.      lb.  440.  f.  5.        auriculifera.      lb.  f.  10. 

Tomella  Sw.  Fusiform,  smooth  ;  the  spire  of  very 
few  whorls,  and  not  longer  than  the  channel ;  inner 
lip  with  a  thick  callosity  at  the  top  ;  the  slit  short  and 
wide. 

lineata.  En.  Meth.  440.  f.  2.     filosa.     En.  Meth.  440.  f.  6. 
clavicularis.      lb.  f.  4.  lineolata.  lb.  f.  11. 

*  In  the  two  typical  groups,  the'notch  is  a  long  slit ;  in  the  three  aberrant 
genera,  it  forms  a  wide  but  short  sinus. 

+  The  aberrant  species  of  this  genus  connects  the  sub-family  with  the 
Columbellince  by  means  of  Crassispira.  They  are  mostly  small  and  rare 
shells. 


PART  II. 


CERITHIXiE. 


315 


SuB-FAM.  5.     CERITHIN^. 

Shell  clavate^  generally  mucronate  ;  the  spire  very  long  : 
the  outer  lip  considerably  dilated  ;  the  base  either  trun- 
catCj  or  forming  a  short  recurved  channel. 

PoTOMis  Brong.  Fluviatile  ?  covered  with  a  brown 
epidermis  :  whorls  coronated^,  and  armed  with  spines  ; 
aperture  almost  entire,  the  notch  being  slightly  de- 
veloped ;  top  of  the  outer  lip  with  an  obsolete  sinus, 
muricata.  Sow.  Man.  377.* 


granulata.  En.  M.  442.  f.4. 


PiRENA  Lam,     Fluviatile ;  smooth  ;  outer    lip     ^. 
much  dilated,  with  a  deep  narrow  slit  on  the    /3 
upper  part;    base  widely    notched;    inner   lip 
entire  and  thickened. f 

P.  terebrans.      Sow.  Man.  f.  316.  {fig.  80.) 

^Terebralia  Sw.  Outer  lip  much  dilated, 
generally  uniting  at  its  base  to  the  inner 
lip,  leaving  a  round  perforation  at  the  base 
of  the  pillar ;  channel  truncate  ;  operculum 
round. 


80 


palustre.     Mart.  f.  1472. 
sulcatum.      En.  M.442.  f.  2. 
Ebenium.      lb.  442.  f.  1. 


heteroclites.     Lam.  No.  24. 
telescopium.  Voy.  Ast.  pi.  55. 
f.  4—6. 


lineatum. 


Rhinoclavis  Sw.  Channel  curved  backwards  in  an 
erect  position  ;  inner  lip  very  thick,  with  a  tumid 
margin  ;  pillar  generally  with  a  central  plait ;  oper- 
culum ear-shaped. 

obeliscus.  En.  Meth.  443.f.  4. 
aluco.    lb.  f.  5.  (Aberrant.) 
semi-granosum.  lb.  443.  f.  1. 
asperum.   Mart.  157.  f.  1483. 

Cerithium  Lam.  Channel  short,  nearly  straight ;  pillar 
smooth  ;  inner  lip  thickened  only  at  the  top,  where 


En.  M.  443.  f.  3. 
lb.  f.  2. 
subulatum.    Lam.  No.  23. 
fasciatum.  Mart.  157.  f.  1481. 


vertagus 


*  Connecting  this  with  the  last  sub-family  by  means  of  Clavicantha. 
f  Representing  Pleurotoma. 


316 


SHELLS    AND    SHELL-FISH. 


PART  II. 


it  forms  a  short  internal  channel ;  operculum  ear  - 

shaped. 

nodulosum.    En.  Mdth.  442,     tuberculatum.      Mart.    157. 
f.  3.  f.  1490. 

Family  4.  VOLUTID^. 

Shell  destitute  of  a  channel ;  the  base  truncated  and 
notched ;  the  piUar  marked  with  folds  or  plaits  ;  oper- 
culum none. 

SuB-FAM.    1.    VOLUTINiE.      True  Volutes. 

Spire  shorter  than  the  aperture^  which  is  never  striated; 
pillar  with  distinct  plaits^  the  upper  ones  the  shortest ; 
tip  of  the  spire  papillary.*  {fig.  81.) 


Voluta  Linn.     Shell  large,  ventricose  ;  the  spire  ex- 
tremely short,  very  obtuse,  and  papillary  ;  the  ter- 
minal whorls,  where  they  exist,  being  smooth  and 
unsculptured. 
1.      Turbinelliform    type.        Shell  melon-shaped;  spire  very 

*  Except  in  Volutiliihes,  •which  wants  the  three  last  characters,  —  the 
plaits.being  faint,  the  tip  of  the  spire  acute,  and  the  lower  plaits  the  longest. 


PART   II. 


VOLUTINS. 


317 


short,     sometimes    nearly 
obsolete.  {Jig-  81.  6.) 

diadema.      En.  M.  388.  f.  2. 

armata.   lb.  388.  f.  1. 

tessellata.   Mart.  f.  781. 

^thiopica.  En.  M.  388.  f.  3. 

melo.      lb.  389.  f.  1. 

Neptmii.    lb.  386.  f.  1. 

Cymbium.      lb.  f.  3. 

proboscidalis.      lb.  389.  f.  2. 

Olla.      lb.  385.  f.  2. 

rubiginosa.   Ex.  Conch.  28. 

porcina.   En.  M.  386.  f.  2. 

2.  Muriciform  type.  Shell 
heavy,  less  ventricose,  co- 
ronated with  cylindrical 
or  vaulted  spines ;  spire 
more  produced. 


marmorata.  Ex.  Conch,  pi.  l. 
chrysostoma.     lb.  pi.  45. 
imperialis.  En.  Meth.  382. 1. 

3.  Strombiform  type.  Outer 
lip  dilated,  and  angulated 
above. 

scapha.  En.  Meth.  391. 
Exotic  Conchology,  pi. 48. 

4.  Ancilliform  type.  Aper- 
ture very  wide ;  spire 
pointed. 

angulata  Sw.  Ex.  Conch, 
pi.  3,  4. 

5.  Marginellifomi  type. 
Shell  partially  polished ; 
ventricose. 

magnifica.  Chem.  174,  175. 
fulgetrum.    Sow.  Tank.  C. 


Cymbiola  Sw.  Spire  more  produced;,  but  not  more 
than  half  as  long  as  the  aperture  ;  the  terminal  whorls 
regular  and  sculptured ;  plaits  on  the  pillar  four. 
{fig.  81.  «.) 


1.  Type  9    Ancilla.  En.  Meth. 

385.  f.  3. 
magellanica.     lb.  f.  1. 

2.  Vespertilio.       En.     M^th. 

378.  f.  2. 
nivosa.     Ex.  Conch,  pi.  5. 


pacifica.  Chem.  178.  f.  1713, 
1714.    Ex.  Conch,  pi.  14. 
festiva.     ?  Lam.  No.  42. 

3.  Mitis.     Ex.  Conch,  pi.  40. 

4.  Braziliana.       Chem.    176. 

f.  1695,  1696. 


Harpula  Sw.  Spire  developed  as  in 
the  last^  but  the  tip  is  generally  more 
slender,  and  the  plaits  are  numerous. 

1,  Vexillum.  En.  Meth.  331.  f.  1.  {fig.  82.) 
Lapponica.      lb.  381.  f.  3. 

2.  Hebrcea.      En.  Meth.  380.  f.  2. 
musica.      lb.   380.   f.  1. 
thiarella.      lb.  380.  f.  2. 
carneolata.    Mart.  96.  930. 
Guiniaca.      Chem.    178.     f.     fulva.    En.  Meth.  382.   f.  3. 

1717,  1718.  sulcata.    Chem.  149.  f.  1403. 

Isevigata.  En.  Me'th.  379.f.  2.     nodulosa.  Lam.  No.  31. 
polyzonalis.    lb.  379.  f.  1. 


318 


SHELLS    AND    SHELL-FISH. 


PART  II. 


3.  fulminata.  En.  M.  381. f.  2.     5.  Lyriformis.   Zool.  111.  i.  54. 

4.  bullata.   Zool.  111.  ii.  pi.  15.        concinna.  Brod.  Z.  P.  iv.  43. 


nucleus.    Lam.  No.  44. 


mitraeformis.  Lam.  No.  43. 


VoLUTiLiTHES  Sw.     Spire  acutely  pointed ;  plates  gene- 
rally faint^  sometimes  obsolete,    {fig.  81.  e.) 

1.  spinosa.    En.  M.  392.  f.  6.     4.  Cithara.  En.  M.  384.  f.  1. 

5.  bicorona.    En.  M.    384.  f.  6. 
crenulata.    lb.  f.  5. 
costaria.  lb.  383.  f. 
lyra.  lb.  f.  6. 


2.musicalis.  En.  M.  392.f.  4 
muricina.    lb.  383.  f.  1. 

3.  rarispina.  En.  M.  384.  f.  2 
labrella.    lb.  384.  f.  3. 


ScAPHELLA  Sw.  Shell  smooth,  almost  polished;  outer  lip 
thickened  internally  ;  suture  enamelled ;  lower  plaits 
the  smallest;  apex  of  the  spire  various,    {fig.  81.  e.) 

1 .  fuslformis  S'w.  Bligh,  Cat.  Junonia.  Ex.  Conch,  pl.33. 

2.  undulata.  Ex.  Conch,  pi.  27.  3.  stromboides.     (fiff.  12.  a, 
volvacia.  Chem.  f.  1339.  b.  p.  123.) 

Zebra  Sw.    (fig.  81.  c.)        5.  papillosa  Siv.    Sow.  Gen. 


SuB-FAM.  2.     MITRAN^. 

Spire   produced,    acute,  generally  as   long*    or   longer 
than  the  aperture  ;  plaits  4 — 5,  the  lower  smallest.t 

MiTRA.  No  internal  channel  or  groove  at  the  upper 
extremity  of  the  aperture ;  outer  lip  curved  from  its 
two  extremities ;  the  base  of  the  aperture  S3 
not  contracted,  the  interior  always  smooth  ; 
spire  lengthened,  acute  ;  shell  without  co- 
ronating tubercles,  but  not  polished.  Re- 
presenting the  Volutes  and  TurbinellidcB. 

Mitra  Sw.  Shell  entirely  smooth,  or  with 
the  sutures  very  slightly  crenated  ;  aper- 
ture very  effuse  at  the  base.     {fig.  83.) 


episcopalis.  En.  M.  369.  f.  2. 
pertusa.      lb.  369.  f.  1.  3. 
versicolor.    Martyn,  1.  f.  23. 
nivosa  Sw.      Bligh,  Cat. 


ambigua 


Zool.  111.  ii.  30.  f.  2. 
fulva.      lb.  f.  3. 
Terebralis.  En.  M.  369.  f.  5. 
lactea.      lb. -371.  f.  2. 


*  Except  in  ConceheUx. 


+  Except  in  some  MitreolcF. 


PART  II.  MITRINvE.  519 

Thiarella  Sw.  Shell  smooth,  with  the  whorls  coro- 
nated ;  the  hody-whorl  less  ventricose. 

papalis.     En.  Meth.  370.  1.  millepora.    En.  M.  370.  f.  5. 

pontificalis  Lam.    lb.  f.  2.  diadema  Sw.  Bligh,  Cat. pi. 66. 

puncticulata.  Lam.  No.  4.  lugubris.   Zool.  III.  i. 
coronata.    En.  M.  371.  f.  6. 

Scahricola  Sw.  Shell  rough,  with  transverse  elevated 
ridges,  and  longitudinal  striae;  suture  not  coronated; 
aperture  effuse ;  outer  lip  crenated. 

serpentina.    En.  M. 370.  f.  3.  filosa.      Lam.  No.  33. 

scabriuscula.    lb.  371.  f.  5.  granulosa.     En.  Meth.   370. 
crenifera.      lb.  370.  f.  4.  f.  6. 

leucostoma  Sw,   Tank.  Cat.  texturata.      lb.  372.  f.  2. 

granatina.    En.  M.  371.f.  4.  ?  terebralis.  Lam.  No.  11. 

Nehularia  Sw.     Shell  generally  marked  with  transverse 
grooves ;  outer  lip  contracted  above,  effuse  below  ;  the 
margin  smooth  ;  base  of  the  body-whorl  narrowed, 
contracta.  Zool.  111.  i.  pi.  18.      Ancillides.  Zool.  Proc.  iii.  1 93. 

Strigatella  Sw.      Size  very  small ;  spire  thick,  obtuse  ; 

outer  lip  thickened,  and  often  reflected  in  the  middle; 

aperture  smooth. 

Zebra.    En.  M.  372.  f  8.  acuminata.  Zool.  111.  ii.  128. 

llneata   Sw.  lb.  372.  f.  7.  f.  3. 

Tiara  Sw.  Aperture  narrow,  linear,  or  of  equal 
breadth  throughout ;  outer  lip  and  base  of  the  body- 
whorl  contracted,  the  former  generally  striated;  an 
internal  canal  at  the  upper  part  of  the  aperture  ;  shell 
(typically)  turreted,  and  equally  fusiform  :  repre- 
senting the  MuricidcB  and  Cynibiola.  (fig.  84.) 

Tiara  Sw.  Shell  turreted,  fusiform,  costated,  and 
semi-coronated ;  spire  and  aperture  of  equal  length  ; 
internal  striae  slight  or  obsolete,  {fig.  84.  c.) ; 

virgo  Linn,     unfigured.  *  nodosa  Sw.    lb.  373.  f.  2. 

Regina.   Chem.  151.  f.  1444.  plicaria.    En.  M.  373.  f.  6. 

vittata.    Zool.  111.  i.  lyrata.    lb.  373.  f.  1. 

ta;niata.    En.  M.  373.  f.  7.  CafFra.    lb.  373.  f.  4. 

corrugata.  lb.  f.8.  (/^.84.c.)  simplicata.    lb.  373.  f.  9. 

costellaris.  lb.  f.3.  (/9  84.5f.)  melongina.    lb.  373.  f.  9. 

vulpicula.    lb.  373.  f.  5.  foraminata.   Zool.  P.  iii.  194. 

*  I  have  once  seen  this  beautiful  shell,  the  rarest  and  most  slender  of 
this  genus. 


320 


SHELLS    AND    SHELL-FISH. 


PART  II. 


Costellaria  Sw.  Unequally  fusiform  ;  the  spire  longer 
than  the  aperture  ;  body- whorl  slightly  ventricose, 
but  suddenly  contracted  near  the  base  ;  internal  striae 
distinct ;  whorls  convex,  rarely  angulated  j  the  ribs 
reaching  to  the  suture,  {^fig.  84. 6?.) 

C.  rigida.     Zool.  111.  1st  Series,  pi.  29. 

Callithea  Sw.  Spire  and  aperture  of  nearly  equal  length  ; 
internal  channel  nearly  obsolete  ;  shell  with  longi- 
tudinal linear  ribs,  crossed  with  transverse  striae  and 
bands  ;  base  contracted,     {fig.  84.  e.) 


sanguisuga.  En.Meth.  373. 
f.  10. 


stigmataria.  Chem.  151.  f.  1442, 
1443. 


Cancilla  Sw.     General  shape  of  the  last ;  but  the  whorls 
crossed  by  transverse  linear  ribs,  or  elevated  ridges ; 
internal   canal  wanting  ;  plaits  very  oblique  ;  form 
slender  ;  outer  lip  thin.  {fig.  84.  h.) 
Isabella.   Zool.  111.  ii.  pi.  50.     sulcata.    lb.  pi.  50.  f.  2. 

Pusia  Sw.  Size  very  small ;  spire  thick,  obtuse ; 
outer  lip  thickened,  and  often  reflected ;  aperture 
striated,  with  an  internal  canal. 

microzonis.    En.  Meth.  374.  f.  8. 

MiTREOLA  Sw.  Small ;  unequally  fusiform  ;  the  base 
obtuse  ;  inner  lip,  typically,  thickened,  inflected,  and 
either  toothed  or  tuberculated  ;  plaits  on  the  pillar 
distinct,  the  inferior  largest ;  tip  of  the  spire  some- 


PART  II. 


OLIVIX.^. 


321 


times  papillary ;    aperture   without   either   striae    or 
groove. 

monodonta.  Zool.  111.  ii.  128.  f.  1.     terebellum.    lb.  f.  2. 

CoN(ELix  Sw.  Small ;  cylindrical  or  conic ;  spire  ge- 
nerally short  and  thick ;  plaits  on  the  pillar  nu- 
merous ;  exterior  often  decussated. 

C.  conulus.    En.  Meth.  382.  f.  2. 

MiTRELLA  Sw*  Rather  small;  olive-shaped; 
unequally  fusiform ;  always  smooth  and 
polished^  and  sometimes  covered  with  an 
epidermis ;  base  obtuse  and  effuse ;  spire 
nearly  or  quite  equal  to  the  aperture ; 
plaits  of  the  pillar  few_,  oblique^  and  ex- 
tending beyond  the  aperture^  which  is 
smooth  internally.  (M.  bicolor,  ^^.  85.) 

ocellata.  Zl.  111.  v.  pi.  54.  f.  2.      olivaeformis.  Zool.  111.  i, 
fissurata.  En.  M.  371.  f.  1.  ii .  54.  f.  3. 

casta.    Zool.  111.  i.  pi.  48.  fusca.  lb.  ii.  pi.  54.  f. 

bicolor.  Ib.ii.  19.  f.2.  (Jig. 85.)  dactylus.   En.  M.  372 
olivaria.   En.  M.  371.  f.  2. 


pi.  48. 

1. 
.  f.  5. 


SuB-FAM.  3.     OLIVINiE.      Olives. 

Shell  smooth^  highly  polished  ;  spire  very  short ;  the 
suture  channeled ;  inner  lip  much  thickened ;  plaits 
numerous,  crowded,  extending,  in  the  typical  genus, 
the  whole  length  of  the  aperture,    (fig.  86,  87.) 

Lamprodoma  Sw.  Mitriform  ;  spire  pro- 
duced, conic;  resembling^jTzYreZ/a  in  shape, 
but  the  suture  is  channelled  ;  the  aperture 
effuse  at  the  base,  contracted  above  ;  lower 
half  of  the  pillar  with  6-7  plaits, 
volutella.  Zool.  111.  ii.  series,  pi.  40.  f.  1.  (fig.86.) 

Oliva  Lam.    Cylindrical ;  spire  very  short, 

pointed;  pillar  with  numerous  slender  plaits ;  aperture 
narrow;  the  base  not  effuse,  {fig. 87.  c.) 
O.  maura.      Sow.  Man.  f.  457. 


322 


SHELLS    AND    SHELL-FISH. 

87 


PART  II. 


ScAPHULA  Sw,  (fig.  87-  &.)  Spire  very  short,  thick,  ob- 
tuse, and  not  defined ;  aperture  very  wide,  with  only 
two  or  three  obhque  plaits  at  the  base. 

S.  patula   Sow.  Tank.  Cat.  2331.  (6.) 

HiATULA  Sw.  {fig.  87.  «.)  General  shape  of  Oliva  ;  but 
the  upper  part  of  the  pillar  is  not  thickened  ;  the 
lower  tumid,  and  marked  with  a  few  oblique  plaits ; 
the  aperture  wide,  the  base  effuse. 

Lamarckii.  Zl.Il.  ii.  p.78.f.  1.      maculosa.  lb.  78.  f.  3. 
pallida.   lb.  78.  f.  2.  ?  striata.   lb.  pi.  40.  f.  2. 

O liveijI. A  Sw.*  (fig.  87-  e.)  Oliviform;  spire  (typically) 
rather  produced ;  the  tip  acute  ;  inner  lip  not  thick- 
ened ;  outer  lip  straight ;  base  of  the  pillar  curved  in- 
wards, and  marked  by  two  strong  plaits  ;  upper  plaits 
obsolete  or  wanting ;  aperture  effused  at  the  base  only. 

biplicata.   Tank.  Cat.  2332.      eburnea.  Zool.  111.  ii.  58.  f.  2. 
purpurata.  Zl.  111.  ii..  58.  f,  1.     conoidalis  La7n.  No.  57. 
mutabilis   Sai/.  oryza  Lam.  No.  62. 

SuB-FAM.  4.     ANCILLARINiE. 

Shell  oliviform,  highly  polished  ;  aperture  very  effuse  ; 
suture   concealed  by  enamel ;    base    with  one    or    two 

*  The  union  of  the  VolutidcB  and  the  TtcrbinellidiB  is  so  intimately 
effected  by  Olii'clla  biplicnla  and  Pseudoltvn  plumhea  {see  Jig.  '3.  p.  Si?.),  that 
the  two  plaits  on  the  pillar  of  the  former  shell  alone  separate  the  two 
families. 


PART  II. 


MARGINELLINiE. 


323 


strong  grooves,  which  form  a  little  tooth 
at  the  edge  of  the  outer  lip ;  inner  lip 
wanting ;  base  of  the  pillar  thick,  vitreous, 
obliquely  striated,  and  turned  outwards. 

Ancillaria   Lam.        The    characters,  at 
present,  are  those  of  the  sub-family,  as 
the  genera  have  not  been  worked  out. 
A.  glabrata  Sw.  {fig.  88.) 

SuB-FAM.  5.     MARGINELLIN^E. 

Shell  small;  oval;  spire  short  or  concealed;  outer  lip, 
and  often  the  inner,  very  much  thickened  and  inflexed, 
with  the  inner  margin  tcrenated ;  pillar  with  distinct 
plaits  ;  the  base  with  a  wdde,  but  not  a  deeply  cleft 
notch. 

VoLUTELLA  Sw,  BulHform  ;  ovate  oblong ; 
spire  either  entirely  or  almost  concealed  ; 
pillar  with  four  oblique  plaits  at  the 
base  ;  aperture  not  striated ;  outer  lip 
smooth,  thickened;   inner    lip  w^anting. 

{fig-  m 

V.  bullata.  Chemn.  150.-   f.  1409-10. 
oblonga,  Zool.  111.  ii.  pi.  44.  f.  1 
guttata.  lb.  £  2. 

Persicola  Schiim.      General  form  of    Volutella ;    but 
the  spire  always  concealed  ;  plaitsnumerous, 
and  extending  nearly  over  the  whole  of  the 
pillar;  the  aperture  striated;  inner  lip  thick 
ened,  spreading. 

avellana.  En.  M.  377.  f.  5.     lineata.  En.M.  377. 
maculata  Sw.  lb.  f.  3.  f.  4.  {fig.  90.) 

Gibber ULA  Sw.     Sub-oval ;   spire  slightly  prominent ; 
top  of  the  outer  lip  dilated  and  gibbous  ;  base  of  the 
inner  lip  with  plaits  ;  inner  lip  broad,  spreading. 
G.   zonata.   En.  Meth.  374.  f.  6. 

Marginella  Lam.     Oval ;   spire  slightly  prominent  ; 

Y   2 


324  SHELLS    AND    SHELL-FISH.  PART   II. 

inner  lip  very  much  developed^  and  forming  a  tumid 
rim  all  round  the  aperture. 

M.  lactea  Sio.     Sow.  Gen.  f.  3. 

Glabella  Sw.  Volutiform  ;  the  spire  more 
or  less  conic,  and  well  developed ;  pillar 
with  basal  plaits  ;  inner  lip  obsolete  ;  outer 
lip  thick_,  toothed,  or  crenated ;  rarely 
smooth.*   (^fig.  91.) 

P.  ruffina  Sw.      En.   Meth.     nubicola.  En.  M.  377.  f.  2. 
377.  f.  6.  bifasciata.  lb.  f.  8. 

Goodalli.  Tan.  Cat.  2151  a.  limbata.  lb.  376.  f.  3. 
If  aba.  En.  Meth.  377.  f.  1.    casrulescens.  lb.  376.  f.  8. 

Family  5.  CYPR^ID^.      Cowries. 

Oval ;  polished  ;  spire  entirely  concealed  ;  aperture  as 
long  as  the  shell,  narrow,  and  open  at  each  end  ;  outer 
lip  generally  thickened  and  inflected. 

SUB-FAM.    1.      CYPR.^IN^. 

Inner  lip  striated  or  toothed. 

Cypb^a    Linn.       Shell    always    entirely 

smooth  ;   the  extremities  of  the  aperture 

obtuse ;     the    teeth    marginal,  and    not 

extending  over  the  circumference  of  the 

lips. 

C.  Arabica.    Sow.  Man.  f.  445,  446. 
caput-serpentis  Lam.  {Jig.  92. ) 

PusTULARiA  Sw.  Shell  generally  marked  by  elevated 
pustules ;  aperture  very  narrow,  and  linear  ;  the  ex- 
tremities more  or  hss  produced  ;  the  teeth  continued 
beyond,  and  frequently  forming  elevated  striae  across, 
the  lips. 

P.  cicercula.  En.  Meth.  355.         globulus.  (Aberrant.)  En. 
f.  1.  ^    Meth.  356.  f.  2. 

*  M.  ccei'ulescens  Lam.  {prunum  Linn.)  unites  this  type  to  Volutella. 


PART  II.  OVITLIN.I:.  325 

Trivea  Grai/.  Shell  marked  with  transverse,  unin- 
terrupted, elevated  lines,  uniting  with  the  teeth  ;  the 
aperture  wide,  and  the  extremities  obtuse  ;  inner 
lip  with  a  thickened  protuberance  ;  pillar  concave 
within, 
coccinella.   En.  M.  356.  f.  1.  Pediculus  Aiict. 

Cypr^dia  Sw.  Cypraeform ;  the  base  contracted  ; 
the  body-whorl  not  flattened  beneath  ;  shell  cancel- 
lated ;  aperture  of  equal  breadth  throughout ;  a  few 
thickened,  short  teeth  on  the  pillar  ;  lip  at  the  base, 
which  is  not  internally  concave,* 

C.  cancellata  Siv.     Sp.  Nov. 

CypK^ovAt  Gray.     Cyprgeform  ;'teeth  of  the  inner  lip 
wanting,  being  represented  by  fine  raised  lines  con- 
tinued  on  the  back  of  the   shell ;    aperture  rather 
effuse ;  top  of  the  outer  lip  much  projecting. 
C.  capensis.     Sow.  Man.  f.       algoensis  Gray.  (Aberrant. ) 
444.  Sow.  Man,  f.  447. 

SuB-FAM.  2.     OVULTN^ 

Oviform ;    smooth,   polished ;    the    extremities  of  the 
aperture  more  or  less  produced  ;  inner  lip  without  teeth. 

Cypr^lla  Sw.  Cyprseform ;  inner  lip  thickened 
above  into  a  point  as  long  as  the  outer  lip,  the  mar- 
ginal teeth  of  which  are  very  regular  ;  a  circular  de- 
pressed line  at  each  extremity. 

C.  verrucosa!  En.  Meth.  357.  f.  5. 

OvuLA  Lam.  Oviform  ;  top  of  the  outer  lip  elevated 
and  produced  beyond  that  of  the  inner,  which  is 
turned  and  much  thickened  ;  both  lips  equal  at  their 
base,  and  slightly  produced. 

O.  ovum.  En.  Meth.  358.  f.  1. 
BiROSTRA  Sw.     The  two  ends  of  the  aperture  suddenly 

*' Fossil  only  ;  differing  from  Trivea  in  its  contracted  base,  in  the  equa- 
lity of  its  aperture,  and  the  equal  convexity  of  the  inner  lip  within, 
f  Abbreviated  from  Cyprcsovulum.    This  seems  the  strombiforra  type, 

Y    3 


326 


SHELLS    AND    SHELL-FISH. 


PART  II. 


contracted  and  produced  into  two  long  beak-like  pro- 
cesses ;  aperture  effuse  ;  the  outer  lip  inflected^  but 
not  toothed. 

B.  volva.   En.  Meth.  357.  f,  3. 

Carinea  Sw.  Oblong  ;  the  extremities  not 
produced  ;  aperture  nearly  straight,  almost 
central,  contracted  above,  and  very  effuse 
below ;  lips  equal ;  the  outer  slightly 
toothed. 

C.  gibbosa.  En.  Meth.  357.  f.  4.  (Jig.  93.) 

VoLVARiA  Lam.  Cylindrical ;  lengthened  ;  the  ex- 
tremities obtuse ;  the  surface  sculptured  ;  base  of  the 
pillar  with  3 — 5  distinct  plaits ;  outer  lip  crenated  ; 
aperture  linear  ;  fossil. 

V.  concinna.    Sow.  Man.  f.  439.  (/^.  94.  a.) 

04. 
Oylindrella  Sw.  Cylindrical,  narrow,  and 

obtuse,  as  in  Volvaria ;  but  the  surface 

and  outer  lip  are  smooth,  and  there  are 

no  plaits  on  the  pillar. 

C.  alba   Sw.  {fig.  94.  I. ) 

Erato  Risso.  Ovate,  more  or  less  angulated,  smooth 
or  granulated,  with  a  dorsal  scar,  short  spire,  and 
large,  angulated,  emarginated  aperture  ;  pillar  slightly 
crenated ;  outer  lip  reflected,  and  denticulated  on  the 
inner  edge ;  sutures  covered  with  enamel.* 


E.  Maugeri. 

A, 


Sow.  Man.  43.  f.  454. 


Order  PHYTOPHAGA. 


Family  1.   HELICIDiE.     Snails. 

Animal  pulmonary  ;    breathing  by  a  lateral   opening  ; 
shell   light,    turbinated,    or  spiral ;  the  aperture  always 

*  I  have  not  seen  this  curious  little  genus.  Mr.  Sowerby,  in  addition  to  the 
above,  adds,  "  it  resembles  Marginclla,  but  has  no  folds  on  the  pillar.  Hav- 
ing a  groove  down  the  back,  he  considers  it  intermediate  between  Margi- 
nella  and  Cyprcea,'"  (or  rather  Trivea),  The  circle  of  the  Cyprceidce  is 
thus  closed,  and  its  union  with  the  Volutidce  at  once  established. 


PART   II. 


LIMACIN^. 


327 


entire,  rarely  closed  by  an  operculum_,  and  sometimes 
only  rudimentary. 

SuBFAM.  1.    LIMACIN^.     Slugs. 

Shell  very  thin,  often  rudimentary,  and  generally  too 
small  to  contain  the  entire  animal ;  tentacula,  when 
present,  cylindrical,  and  bearing  the  eyes  at  their  tip. 

Herpa.  Tentacula  two,  or  none  ;  shell  none  ;  jaws 
none,  or  not  discernible. 

Herpa  Guild.     Linear,    fusiform,    anterior   greatly    at- 
tenuated ;  eyes  very  small,  sessile ;  tentacula  none. 
H.  gigas.      See  App.  '-~  /^ 

Onchidium  Buch.  (fig.  95.)  Tentacula 

two ;  mantle  very  large,  tuberculated, 

almost  covering  the   body  ;    mouth 

with  two  triangular  flattened  lobes. 

;  Typhoe  Buck.  Lin.  Tr.  v.  132. 

LiMAx  Linn.  Tentacula  four  ;  shell 
rudimentary,  or  none. 

Limax  Linn.  Orifice  near  the  pos- 
terior part  of  the  mantle  ;  shell 
very  small. 

L.  variegatus.      GrifF.  Cuv.  pi.  35.  f.  2. 

Avion  Fer.  Orifice  near  the  anterior  end  of  the  man- 
tle ;  shell  none. 

A.  empiricorum.      GrifF.  Cuv.  pi.  35.  f.  1. 

Vaginula  Fer.  Mantle  large,  covering  the  whole  body  ; 
no  shell. 

V.  Taunaysii.      Griff.  Cuv.  p].  35.  f.  7. 

Parmacella  Lam.  Mantle  moderate,  membranaceous, 
placed  on  the  middle  of  the  back ;  the  edges  loose  ; 
shell  oblong,  flat ;  spire  minute. 

P    Olivieri.      Griff.  Cuv.  pi.  35.  f.  5. 

Testacella  Lam.     Mantle  very  small,  and  placed  at  the 
posterior  extremity  of  the  body ;   shell  small. 
T.  haliotoidea.      Griff.  Cuv.  pi.  35.  f.  4. 
Y    4 


328  SHELLS    AND    SHELL-FISH.  PART  11. 

ViTRiNA  Drap*  Mantle  with  a  double  border ;  the 
upper  one  lobed,  and  folded  back  upon  the  shell ; 
posterior  part  of  the  body  obtuse,  truncate ;  shell 
slightly  turbinate,  thin,  ear-shaped,  polished ;  too 
small,  in  general,  to  contain  the  animal. 
V.  pellucida,     Drap,   Moll. 

Stenopus  Guilding.     Body  linear,  long ;  the  disk  very 
narrow,  superior ;  tentacula  thickened,  clavate  ;  shell 
thin,  nearly  discoid,  nearly  equal  to  the  animal. 
S.   cruentatus    Guild.    Zool.  Journ.  iii.  pi.  15.  f.  1 — 5. 

SucciNEA  DrapA  Shell  nearly  equal 
to  the  animal ;  oblong,  thin  ;  spire 
short,  pillar  none  ;  aperture  very 
large. 

S.  amphibia.  Sow.  Man.  f.  265.    {jig.  96.) 

SuB-FAM.  2.    LUCERNIN^E.    Land  Volutes,  or  Lamp  Snails. 

Shell  discoid ;  the  spire  scarcely  raised  ;  the  substance 
solid ;  surface  either  granulated  or  striated  ;  aperture 
generally  toothed. 

Leiostoma  Sw.  Shell  patulous;  the  aperture  very 
large  and  wide  ;  spire  of  only  two  or  three  small 
whorls  ;  outer  lip  reflected. 

Leiostoma  Sw.  Surface  granulated ;  a  transparent 
glazing  extending  far  beyond  the  inner  lip. 

gigantea.    Fer.  15.  f.  5,  6,7.      vesicalis.   Chem.  208.  f.  2051, 
Jamaicensis.    lb.  14.  f.  6—8.  2052. 

LucERNA  Humph.  Shell  discoid,  of  several  graduated 
whorls ;  the  surface  granulated ;  the  spire  slightly 
elevated  ;  circumference  carinated ;  teeth,  Avhen  pre- 
sent, on  the  outer  lip  only. 

Caracolla  Lam.  Aperture  circular ;  the  two  lips  united; 
teeth  none  ;  umbilicus  open, 
lapicida.  Chem.  f.  1107.     tectiformis.  Zool.  J.  i.  pi.  3.  f.  6. 

*  The  sub-genera  remain  to  be  determined, 
f  The  same  remark. 


PART  II. 


LUCERXIN^.  329 


Discodoma    Sw.       Teeth    none ;     aperture    angulated ; 
the  inner  lip  nearly  obsolete,  the  outer  only  slightly 
thickened ;   margin  carinated. 
albilabris.  Chem.  125,f.  1090,      Gualteriana.    Chem,  5.   vig. 

1091.  44.  a—c. 

inflata.     lb.    126.  f.  1 100,  1.      marginata.    lb.  102.  f.  1095. 
gigas.     lb.   f.  2044,  5.  angistoma.    lb.  125.  f.  1092. 

Lucerna  Humph.      Outer  lip  with    teeth,  either    mar- 
ginal or  internal ;   the  outer  lip  thick  and  reflected  ; 
circumference  carinated. 
acutissima.      Zool.     111.  ^  ii.      fasciata  Guild.    Bow.  Conch. 

pi.  96.*  '  7.  f.  23. 

lanx.  En.  Meth.  462.  f.  2.         fulgurata  Sow.\ 
lychnuchus.  Ch.  126.  f.  1108.      sinuata.     Chem.  126.  f.  1110 

— 1102.  (Aberrant.) 

Anastoma  Lam.  Aperture  turned  upwards,  furnished 
with  plaited  teeth  on  both  sides. 

A.  depressa.    Chem.  109.  f.  919,  920. 

LucAdula  Sw.  Aperture  transverse ;  both  lips  much 
thickened  and  united  ;  the  outer  with  marginal  obso- 
lete teeth  at  the  base  ;  umbilicus  closed. 

'  Barbadensis  Lam.    No.  49.  p.  78.  Fer.  Moll.  pi.  47.  2,  3,  4. 

LucERNELLA  Sw.  Teeth  on  both  sides  of  the  aper- 
ture ;  surface  regularly  and  distinctly  striated.  Cir- 
cumference convex.:}: 

Polydontes     Montf.       Aperture    nearly    circular,    sur- 
rounded with  obtuse  tubercular  teeth. 
P.  imperator.    Bowdich,  Elem.  of    Conch,  pi.  7.  f.  21. 

Lyrostoma  Sw.  Aperture  lyre-shaped,  very  contracted 
near  the  body-whorl,  widened  beyond. 

L.  labyrintha.     Chem.  pi.  208.  f.  2048.     Lam.  p. 46. 

*  The  original  figure  of  the  shell  and  animal  given  in  Zool.  111.  is 
copied  by  Feriissac,  Guerin,  and  numerous  others,  but  so  badly,  that  the 
shell  appears  to  be  a  totally  different  species. 

f  Mr.  Sowerby  has  published  a  very  beautiful  detached  plate  of  this 
species,  first  described  by  himself. 

X  Some  slight  variation  has  been  made  in  the  arrangement  of  this  group 
from  that  previously  stated  at  p.  193.  Cyclodoma  is  here  united  to  Lucer- 
nella,  and  the  new  sub-genus  Lyriostoma  proposed. 


330  SHELLS    AND    SHELL-FISH.  PART  II. 

Lucernella  Sw.     Shell  small,  striated ;  outer  lip  with 
marginal,  not  internal,  teeth  ;  inner  lip  with  an  ele- 
vated toothlike  plate;  umbilicus  generally  pervious. 
L.  hippocastaneum.    Chem.  209.  f.  2055,  2056. 

Polygyra*  Shell  completely  discoid ;  no  pillar  ;  aper- 
ture angulated  and  margined ;  a  small  tooth  on  the 
inner  lip. 

P.  septemvolvus.  Sow.  Man.     carabinata.       Bow.     Conch, 
f.  275,  276.  pi.  7.  f.  1  9. 

Lucidella  Sw.  Sub-trochiform  ;  spire  conic,  and  sud- 
denly pointed ;  outer  lip  with  marginal  tuberculated 
teeth,  f 

L.  aureola.      Zool.  Journ.  i.  pi.  6.  f.  15. 

PusiODON  Sw.  Shell  flattened,  smooth ;  the  body- 
whorl  large,  and  much  dilated  at  the  aperture  ;  spire 
small,  flat,  of  three  or  four  contracted  whorls  ;  aper- 
ture very  oblique,  sinuated,  or  obsoletely  toothed  at 
the  base  of  the  outer  lip,  which  is  spreading  and  sub- 
reflected  ;  inner  lip  obsolete ;  umbilicus  open, 
zonaria.  Chem.  132. f.  1188.     auriculata.  Zool.  111.  i.  pi,  6. 

f  J*"'>2  Thelidomus  Sw.  Shell  coarsely  granulated ;  body- 
"^  whorl  and  spire  as  in  the  last  genus ;  but  the  former 
is  more  ventricose,  and  the  latter  more  raised,  and 
somewhat  distorted ;  outer  lip  thickened  and  reflected ; 
the  base  broad  and  flattened,  sometimes  with  granu- 
lated marginal  teeth  ;  umbilicus  none. 
T.  (Helix)  striolata  Guild,   also   Fer.  Moll.  44.  f.  1-4. 

SuB-FAM.   3.      HELICIN^.       Common  Land  Snails. 

Shell  ventricose,  turbinated  ;  the  aperture  transversely 
oval,  never  toothed  ;  the  body- whorl  large  and  ven- 
tricose. J 

Helix.  Linn.  Shell  globose,  turbinate  ;  body-whorl 
ventricose ;  spire  slightly  raised,  obtuse. 

*  I  find  this  name  as  above  quoted,  but  no  mention  is  made  in  the  text  of 
whose  genus  it  is. 

f  I  have  been  obliged  to  designate  what  seem  to  be  the  types  of  this  ge- 
nus, in  order  to  show  more  clearly  its  union,  on  one  side  witii  Cvclostoma, 
and  on  theotherwith  Claiisilia,  or  the  toothed  division  of  the  Achatin^e  . 
Mr.  Gray's  valuable  paper  may  be  consulted  with  much  advantage 

t  Except  in  Pupa,  which  has  teeth,  and  a  small  body-whorl. 


PART  II.  HELICIN^.  331 

HemicycJa  Sw.  Shell  discoid ;  spire  rather  flattened, 
but  not  small,  and  of  four  whorls  ;  outer  lip  semicir- 
cular, dilated  into  a  broad,  flat  margin,  but  not  re- 
flected ;  inner  lip  nearly  obsolete,  but  sometimes 
with  a  small  obsolete  tooth  ;  umbilicus  none  ;  sur- 
face distinctly  striated. 

H.  plicaria.   En.  Meth.  462.  f.  3. 

Helix  And.  Body- whorl  ventricose ;  spire  more  or  less 
conic,  but  always  shorter  than  the  aperture  ;  umbili- 
cus almost  always  closed,  or  not  existing ;  outer  lip 
reflected  or  thickened. 

pomatia.  Chem.  128.  f.  1138.     hoemastoma.  Ch.  130.  f.ll50. 
aspera.    Penn.  pi.  87.  f.  3.  melanotragus.      En.     Meth. 

lactea.  Chem.  1 20.  f.  1 1 6 1 .  462.  f.  4. 

Zonites  Montf.      Shell  sub-ventricose,  but   the    body- 
whorl  depressed,  the  margins  convex  ;  spire  often  of 
many  whorls ;  outer  lip  thin  ;  umbilicus  open, 
unizonalis.  En.  M.  462.  f.  6.      citrina.    Chem.  131.  f.  1177. 

Epistyla  Sw.  Shell  very  thick,  conic,  and  obtuse  ;  the 
whorls  very  numerous ;  body-whorl  and  aperture 
small ;  outer  lip  thin. 

E.  conica  Sw.  Sow.  Man.  f.  281. 

Streptaxis  Gray.  Heliciform  ;  but  the  pillar  or  axis 
not  perpendicular,  which  gives  the  body-whorl  a  dis- 
torted appearance  ;  umbilicus  small,  open ;  spire  of 
six  whorls  ;  outer  lip  thickened. 

S.  contusa  Gray.      Sow.  Man.  f.  269,  270. 

Geotrochus  Sw.  Shell  somewhat  spiral;  the  spire 
being  conical,  often  trochiform,  and  always  longer 
than  the  aperture,  which  is  transverse  and  without 
teeth. 

Hemitrochus  Sw.  Whorls  convex  ;  spire  conic,  obtuse, 
not  longer  than  the  aperture ;  outer  lip  having  a 
thickened  rim  inside  the  margin,  which  is  acute ; 
umbilicus  closed. 

H.  hoemastomus   Sw.     {See Jig.  19.  p.  165.) 


332  SHELLS    AND    SHELL-FISH.  PART   II. 

Geotrochus  Sw.     Trochiform  ;   the  body- whorl  more  or 

less  carinated ;  the   spire  pointed  and   acute  ;  outer 

lip  thickened   and  reflected,   inner  almost  obsolete  ; 

umbilicus  almost  obsolete. 

pileus  Zool.  111.  ii.  pi.  91.       Ferussacii  Lesson,  Voy.  8.  f.  5. 

Pythohelije  Sw.  Sub-spiral ;  body-whorl  large,  ven- 
tricose,  and  hardly  angulated  ;  spire  convex  and  ob- 
tuse ;  outer  lip  thickened  and  reflected,  generally 
separated  from  the  pillar  by  a  sinus  ;  umbilicus  none; 
aperture  nearly  round. 

P.  castanea   Sw.      Bow.  Conch,  pi.  8.  f.  27. 

Geomitra  Sw.     Conic,  thick,  obtuse  ;   the  whorls  stri- 
ated, and  coronated  with  tubercles ;  body- whorl  small ; 
aperture  very  small,  circular ;  lips  united,  the  outer 
one  thin  ;  umbilicus  small, 
bicarinata.      Zool.  Journ.  i.  pi.  3.  f.  7.   {fig-  20.  p.  166.) 

Gonidomus    Sw.       Conic,    thick,    obtuse ;     the    spiral 
whorls  distorted ;    body-whorl  contracted ;    aperture 
oval,   perpendicular ;  the   lips  thickened  ;  umbilicus 
open,  but  not  deep.* 
?  pagodus.     Lesson,  Voy,  pi.  8.  f.  6.   (fig.  21.  p.  166.) 

Pupa.  Shell  cylindrical;  the  spire  much  produced; 
the  middle  whorls  thicker  than  the  body-whorl ; 
teeth  generally  on  the  pillar,  but  none  on  the  outer 
lip  ;  aperture  mostly  round. 

Plicadomus  Sw.  Spire  moderate,  regular,  and  thick, 
but  gradually  conic ;  the  tip  obtuse  ;  aperture  perpen- 
dicular ;  inner  lip  wanting  ;  outer  lip  semicircular  ; 
the  margin  dilated  and  reflected. 

P.  sulcata.    Chem.  J  35.  f.  1231,  1232. 
Pupa  Lam.     Spire  thickest  towards  the   middle ;    the 
tip  abruptly  pointed  ;  aperture   oval ;  the  lips  con- 
siderably thickened  and  united ;  a  single  plait  gene- 
rally on  the  pillar. 

P.  mumia.    Mart.  153.   f.  1439. 
*  This  seems  to  represent  Streptaxls. 


PART   II. 


HELICIX.E. 


333 


Gonospira  Sw.  Spire  perfectly  cylindrical,  of  equal 
thickness,  the  tip  obtuse,  with  the  whorls  large  ;  aper- 
ture oval ;  lips  thickened ;  pillar  with  or  without  a 
plait. 

G.  polanga  Desk.     Lesson,  Voy.  pi.  8.   f.  8. 

Megaspira  Lea.     Spire  excessively  long,  of  more  than 

twenty  volutions,  and  of  nearly  equal  thickness  ;   the 

tip  persistent,  and  slightly  pointed;  aperture  rounded; 

outer  lip  thin ;  pillar  and  inner  lip  with  sharp  plaits. 

M.  elatior  Spix.    Test.  Braz.  15.   f.  1. 


Siphonostoma  Guild.      Spire  excessively  long,    pointed, 

but  the  upper  portion  deciduous ;  aperture    circular, 

spreading  ;  the  lips   united,  and   detached  from  the 

adjoining  whorl,   (^fig.  97.  c.  d.) 

S.  costata  Guild,  [jig.  97.  c,  d.} 
fasciata.  En.  Meth.  461.  f.  7. 


Helicella  Feruss.  Shell  discoid, 
but  the  body- whorl  thick  and 
ventricose  ;  the  spire  very  small 
and  sunk  ;  pillar  none ;  aperture 
semicircular  ;  outer  lip  thickened ; 
umbilicus  very  wide.     (^^.  98.) 

pellis-serpentis  (_^^.  98.);     also  Fer. 
MoUus.  pi.  66.    73.    75.  77. 


S34>  SHELLS    AND    SHELL-FISH.  PART  II. 

SuB-FAM.  4.     ACHATIN^. 

Shell  spiral ;  aperture  oblong  or  oval,  always  equal,  and 
generally  shorter  than  the  spire.* 

Clausilia  Drap.  Aperture  oblong,  with  teeth  on  both 
sides  t ;  shell  cylindrical. 

Pupella  Sw.  X  Spire  moderate,  obtuse ;  the  whorls  of 
equal  thickness  ;  basal  whorl  and  aperture  small ; 
the  latter  with  teeth  on  both  sides ;  the  lips  not 
thickened. 

frumentum.  Drap.  3.f.51,52.     vertigo.        Bow.     Conch.    8. 
variabilis.      lb.  f.  55,  56.  f.  35. 

Eruca  Sw.  General  habit  of  the  last  ;  but  the  tip  of 
the  spire  is  thicker,  and  there  is  only  one,  or  no 
plate,  upon  the  inner  lip  only. 

muscorum.  Drap.  3.  f.  36-38.      dolium.      Drap.  3.   f.  43. 
fragilis.      lb.  4.   f.  4.  umbilicata.      lb.  3.  f.  39,]40. 

Balia  Gray.     Spire  very  long,   of  numerous   persistent 
whorls ;  aperture  simple,  without  teeth  or  folds. 
B.  fragilis.      Drap.  pi.  iv.     ventricosa.    Zool.  Journ.  i.  pi. 
f.  4.  5,  6. 

Clausilia  Drap.     Spire  very  long,  but  the  upper  portion 
deciduous  ;  aperture  oblong,  ear-shaped,  with   teeth 
on    both   sides ;   the    lips    united,    and    their    edges 
spreading, 
papillaris.    Drap.  4.  f.  13.  plicatula.     lb.  4.  f.  17,18. 

Macrodontes  Sw,  Size  larger;  bulimiform  ;  spire  longer 
than  the  aperture,  which  is  surrounded  with  large 
teeth  ;  lips  united  ;  the  outer  large,  dilated,  and  the 
edge  reflected.     Tropical  America  only. 

M.  Sowerbeyii  Sw.      Zool.  Journ.  i.   pi.  5.   f.  2. 

2.  BuLiMus.     Basal  whorl  ventricosc  ;  outer  lip   mar- 

*  Except  in  Helicina  and  the  turbinated  Cych'^omce. 

f  Except  in  Balia,  which  has  no  teeth. 

X  Including  the  European  Pupu;,  f'ertigo,  and  A!<e. 


PART  II.  ACHATIN^.  335 

gined  and   reflected;  aperture  without   teeth^  rarely 

with  a  single  fold.* 
Aui'icula    Lam.       Body-whorl     sub-ventricose ;     spire 

short ;  the  whorls  few  ;  pillar  with  one  or  two  plaits  ; 

outer  lip  margined  and  reflected. 
Sileni.  En.  Meth.  460.  f.  4.     leporis.  Lam.  {fig.  27.  p.  181.) 

Bulimus  Lam.     Outer    lip   thickened    and    reflected  ; 
spire  short ;  pillar  smooth, 
melanostomus.    Zool.  111.  i.  4.     Australis.  Bow.  C.  8.  f,  30. 

Bulimulus  Leach.     Outer  lip    thin,  or    sub-reflected ; 
spire  equal  or  rarely  longer  than  the  aperture. 

undulatus  Guild.  Zool.  J.  iv.  169.      Antiguensis.      lb. 
stramineus.   lb.  iv.  170.  Proteus.     lb. 

Leptospira  Sw.     Spire  excessively  long,  sub-cylindrical; 
body-whorl  largest ;    outer  lip   thickened ;  aperture 
oval ;  no  teeth, 
striata  Sw.    Chem.  135.  f.  1226.     signata  Sw.  {fig.  97.  a,h.) 

Goniostoma  Sw.     Spire  elongated,  of  few  whorls ;  aper- 
ture   contracted  at    each    end ;    lips  margined ;  the 
pillar  curving  inwards ;  the  base  slightly  notched. 
T.  erubescens  Sw.       Zool.  Journ.  i.  pi.  5.  f.  2.  t 

3.  AcHATiNA.  Outer  lip  always  thin ;  base  of  the 
piUar  truncated,  or  sinuated,  before  it  joins  the  outer 
lip. 

Macrospira    GuUd.J       Spire    excessively    long,     sub- 
cylindrical  ;    body-whorl  largest ;    outer    lip     thin ; 
aperture  oval. 
M.  octona.  (Helix  octona  Auct.^  aperta  Guild,  (fig.  97.  e,f.) 

Cochlycopa\  Fer.  Oblong;  body-whorl  slender;  sur- 
face striated  ;  spire  variable ;  outer  lip  with  a  promi- 
nent lobe  near  the  base. 

C.glans.   Chem.  117.  f.  1009,  1010. 

*  Only  in  Auricula. 

f  The  singular  lateral  position  of  the  aperture  is  not  expressed  in  this 
figure.     See^^.  25.  p.  177. 
X  Subsequently  named,  inadvertently,  Chionella,  by  Mr.  Jeffreys. 
§  Very  properly  substituted  by  Ferussac  for  Polyphe7nus. 


.336 


SHELLS    AND    SHELL-FISH.  PART  II. 


Achatina  Lam.  Oblong ;  body-whorl  ventricose  ;  sur- 
face smooth  ;  spire  variable ;  outer  lip  without  any 
lobe.      {fig.  23.  p.  170.) 

A.  marginata  Sw.     Zool.  111.  1st  Series,  pi.  30. 

Achatinella  Sw.    Small ;  sub-trochiform  ;  spire  obtuse  ; 
outer  lip  with  a  thickened  internal  margin. 
A.  pica.    Zool.  111.  ii.  Series,  pi.  99. 

Leucostoma  Sw.  General  shape  of  the  last,  but  the 
upper  lip  has  a  thick  pad  at  the  top,  and  another 
over  the  base  ;  affinities  doubtful. 

L.  variegata  Sw.  {fig.  24.  p.  172.) 

Cyclostoma.  Aperture  circular,  and  closed  by  an  oper- 
culum j  the  margins  of  both  lips  united. 

Cyclophora  Montf.  Turbinate  ;  the  spire  very  short, 
and  generally  pointed  _;  umbilicus  very  large ;  aper- 
ture entire. 

unicarinata.  En.  M.  461.  f.  1.  involvula.  Sow.  Man.  f.  304. 

volvula.       lb.  f.  5.  articulata.  Griff.  Cuv.  28.  f.  1. 

lincina.      lb.  f,  2.  pulchra.      lb.  f.  3. 

pulchra.      Sow.  Gen.  f.  2.  Madagascariensis.      lb.  f.  4. 

ligatuni.      lb.  f.  4.  auricularis.      lb.  f.  5. 

Cyclostoma  Drap.  Spiral ;  spire  sub-cylindrical  and 
obtuse  ;  pillar  sometimes  wanting  ;  umbilicus  small, 
or  closed. 

C.  labio.      En.  Meth.  461.  f.  4. 

Cydotus  Guild.  Nearly  discoid  ;  pillar  none  ;  spire 
scarcely  raised,  and  the  tip  obtuse  ;  a  small  siphon 
at  the  top  part  of  the  aperture. 

planorbulus.  En.  M.  461.  f.  3.      variegatus  Sw.  Sow.  Gen.  f.  1. 

Megalomastoma  Guild.  Cylindrical,  resembling  Pupa, 
but  has  a  horny  operculum  ,•  spire  not  thickened ; 
teeth  or  fold  on  the  pillar  none,     {fig,  97-  g^  h,  i.) 

flavula  Sw  En.  Meth.  461.  f.  6.   brunnea  Guild.  (fig.93.g,  h,  i. ) 

Heltcina  Lam.  Shell  turbinate  ;  outer  lip  thickened, 
and  reflected  ;  inner  lip  thick,  and  spreading  over 
the  umbilicus  ;  aperture  semicircular,  or  lunate. 


PART  11.  LIMNACINiE.  337 

Helicina   Lara.     Heliciform ;    aperture   with   an   open 

slit^  or  narrow  fissure  at  the  base. 

major  Gray.  Zool.  Journ.  i.      sub-marginata.  lb.  pi.  6.  f.  11. 
68.  pi.  6.  f.  10. 

Pachytoma  Sw.     Aperture  entire  ;    the  inner  lip  very 

thick  ;  the  spiral  whorls  hardly  convex. 

occidentalis.    Zool.  J.  iii.  15.     viridls.    Zool.  Journ.  i.  pi.  6. 
f.  6—10.  {fig.  28.  p.  184.)  f.  7. 

Oligyra  Say.     Aperture  entire  ;  the  base  of  the  pillar 
produced  beyond, 
rhodostoma.   Zool.  Journ.  i.  pi.  6.  f.  9.      orbiculata  Say. 

Trochatella  Sw,  Trochiform ;  spire  elevated^  acute  • 
inner  lip  very  thin  ;  outer  lip  spreading :  represent- 
ing Cyclophora. 

T.  pulchella.     Zool.  Journ.  i.  pi.  6.  f.  1. 

SuB-FAM.  5.     LIMNACIN^.      River  Snails. 

Animal  pulmoniferous ;  tentacula  two,  often  flat ;  the 
eyes  basal  {fig.  100.  e)  ;  shell  very  thin;  operculum 
none. 

Planorbis.  Shell  discoid,  both  surfaces  nearly  alike ; 
pillar  none ;  aperture  oblique  ;  aperture  reversed. 

Planorbis  Drap.     Spiral  whorls  few  ;  body-whorl  ven- 
tricose. 
P.  corneas.    Drap.  1.  f.  42 — 44.      Sow.  Man.  f.  311. 

Spirorhis  Sw.  Shell  greatly  depressed ;  the  whorls 
very  numerous. 

S.  vulgaris.    Drap.  2.  f.  6,  7. 

Helisoma  Sw.     Shell  ventricose,  the  spire  sunk  below 
the  body-whorl ;  whorls  hardly  three. 
H.  bicarinata.    Sow.  Gen.  f.  4. 

Segmentaria  Flem.*  Shell  greatly  depressed ;  the 
whorls   very   few ;  the   internal   cavity  divided,    by 

*  It  is  not  a  little  extraordinary,  that  no  writer,  that  I  am  aware  of,  Bri- 
tish or  Continental,  has  adopted  this,  the  most  remarkable  t3'pe  among  the 
aquatic  Pulmonaria.  Dr.  Fleming  deserves  much  credit  for  being  the  first 
who  characterised  it. 


338 


SHELLS    AND    SHELL-FISH. 


PART  II. 


transverse  testaceous  partitions,  into'chambers,  which 
communicate  with  each  other  by  triradiated  apertures. 
Representing  the  Cephalopoda. 

S.  lacustris  Flem. 

LiMNEA  Lam.  Very  thin  spiral ;  the  spire 
variable  in  length,  but  always  pointed ; 
aperture  large,  effuse  ;  outer  lip,  typically, 
much  dilated  and  rounded. 

L.  stagnalis.    Sow.  Man.  f.  308.  (Jig.  99.) 
aserta.    lb.  f,  309. 

LeptoUmnea  Sw.  Nearly  cylindical;  spire 
thick,  lengthened,  longer  than  the  aper- 
ture; which  latter  is  small. 

L.  elongata.   Sow.  Gen.  f.  6. 

Physa  Drap.*     Shell  generally  reversed,  smooth,  and 

polished;  aperture  oval,  not  dilated,     {^fig.  100.) 

rivalis.     {Jig.  100.  6.)        fontinalis.  lb.  f.  9.  (Jig.  100.  a.) 
GuUdingii  Sw.     (jig.  100.  c,  d,  e.) 

100 


^" 


PoTOMOPHiLA  Sw.     Shell  resembling  a  Limnea,  but  with 
a  distinct  fold  on' the  pillar. 
P.  bulimoides.   En.  Meth.  459.  f.  7.     (Jig.  31.  p.  187.) 

Ancylus  Lam.     Shell  thin,  patelliform  ;  resembling  a 
limpet. 

A.  fluviatilis.      Sow.  Man.  f.  246. 

Family  TURBID^E. 

Shell  solid,  but  not  perlaceous,  spiral ;  aperture  entire, 
closed  by  an  operculum. 

*  Between  the  shells  of  Physa  and  Lymnca  there  is  no  great  difference ; 
but  their  animals  are  too  distinct  to  be  united  in  any  system  of  malacology. 


PART  II. 


AMPULLA  RlNiG. 


339- 


SuB-FAM.  ?     THALLICERA. 

Th ALLicERA  Q,uoy.     Shell  globose ;    spire    depressed ; 
outer  lip  thin^  with  a  sinus  above ;  inner  lip  thick- 
ened, with  a  prominent  plait  near  the  base. 
T.  avellana.   {Jig.  34.  p.  196.)    Chem.  188.  f.  1919-20. 

SuB-FAM.   AMPULLARIN^. 

Animal  with  a  respiratory  siphon;    shell  globular  or 
turbinate. 

Valvata  Drap*     Shell  turbinate,  sometimes  nearly  dis- 
coid; spire  very  short;  the  whorls  convex;  aperture 
circular ;  operculum  spiral ;  umbilicus  pervious. 
V,  piscinalis.    Sow.  Man.  f.  322. 

Ampullaria  Lam.  Shell  glo- 
bose, rarely  discoid,  turbinate ; 
spire  very  short ;  aperture  ob- 
long, pointed  above,  rounded 
below. 

Ampullaria  Lam.  Outer  lip  thin ; 
operculum  horny. 

fasciata  Lam.  {fig.  101.  a.) 

Pachylabra.f     Outer  lip    thick- 
ened; operculum  shelly, 
globosa^'w.    Zool.  111.  i.  pi.  119. 

Lanites  Montf.     Shell  reversed  ; 

the  body- whorl  ventricose  only  in  the  middle  ;  outer 
lip  generally  thin. 

L.  Guinaica.      Sow.  Man.  f.  319. 

Ceratodes  Guild.  Shell  discoid ;  body-whorl  higher 
than  the  spiral  whorls ;  outer  lip  thin ;  operculum 
horny. 

C.  Cornu-Arietis.      Sow.  Man,  f.  320. 

Paludina.  Spiral;  spire  equal,  or  longer  than  the 
aperture  ;   lips  thin. 

*  Affinities  uncertain. 

t  Pachystotna  Guild.,  already  used  in  Ichthyology. 

z  2 


340  SHELLS    AND    SHELL-FISH.  PART  11. 

Paludina   Lam.     Whorls    inflated ;    umbilicus    open  ; 
operculum  horny  ;  aperture  ovately  round, 
elongata.  Zool.  111.  i.  p\.  98. (Jiff.  101.  b.)     unicolor.  lb.  (c.) 

Nematura  Benson.*     Whorls  slightly  convex;  aperture 
small,  oblique,  contracted  ;  operculum  spiral,  horny. 
Sow.  Man.  f.  305. 

Meladomus  Sw.     Spire    pointed;    aperture    oval,    re- 
versed,  pointed,   and    contracted    above ;    umbilicus 

none ;  operculum } 

M.  bulimoides.  f     Sw.  Sp.  Nov. 


SuB-FAM.     MELANIAN^. 

Shell  spiral  ;  the  spire  always  as  long  as,  and  generally 
much  longer  than,  the  aperture  ;  body-whorl  small.;}: 

Paludomus  Sw.  Shell  oblong-globose,  strong;  spire 
shorter  than  the  aperture ;  inner  lip  very  thick. 

Paludomus.  Shell  smooth ;  outer  lip  slightly  spreading, 
the  margin  crenated  ;  inner  lip  very  thick  and  ena- 
meled.    India. 

P.  globulosa.  GrifF.  Cuv,  xii.     conica.    GrifF.  Cuv.  f.  5. 
pi.  14.  f.  6.  retiisa.     lb.  f.  9. 

Anculosa  Say.     Spire  very  short ;    outer  lip  sinuated, 
thin  ;  top  of  the  inner  lip  thickened  internally  ;   but 
obsolete  in  the  middle,  and  flat  at  the  base.  America. 
pra^rosa  and  monodontoides  Say.  Sow.  Man.  314. 

Hemimitra  Sw.  Resembling  Paludomus ;  but  the 
whorls  are  coronated.     India. 

H.  retusa.     Sw.  Sp.  Nov. 

Melania.  Shell  elongated,  spiral;  the  aperture  oval, 
entire ;  the  outer  lip  dilated  at  its  base. 

•  I  do  not  know  this  type. 

+  Entirely  brownish  black.  The  shape  and  size  similar  to  Bulimus 
ciirinus ;  but  the  outer  lip  thin.     Inhabits  China  ? 

X  Except  in  Paludomus,  which  blends  into  Melado?nus,  and  thus  unites 
this  with  the  last  sub-family. 


PART  II. 


MELANIANiE. 


341 


Melacantha  Sw.     Spire    and  aperture 

nearly  of  equal  length ;  the  whorls 

coronated    with    spines ;    inner    lip 

very  thin. 

M.  amarula   Sw.    Zool.  111.  ii.  pi.  29. 
f.  1.  {fig.  102.  «.) 
setosa  Sw.      lb.  ii.  f.  2. 

Melania    Lam.     Subulate    and    elon- 
gated; inner  lip  wanting,  {^fig.  102.  6.) 

M.  quadriseriata.      GrifF.  Cuv.  14.  f.  3. 

Potadoma  Sw.*    General  characters  of  Melania;  but  the 
outer  lip  is  hardly  dilated,  and  the  top  of  the  inner 
lip  is  internally  thickened, 
P.  Frethii.  GrifF.  Cuv.  14.  f.  2.        l^vis.   lb.  14   f.  8. 

Hemisinus  Sw.  General  shape  of  Melania  ;  but  the 
base  of  the  aperture  is  contracted  and  emarginate ; 
outer  lip  crenated. 

H.  lineolata.      GrifF.  Cuv.  xii.  pi.  13.  f.  4. 

Melanella  Sw  Obovate  ;  spire  scarcely  longer  than 
the  aperture,  which  is  entire  ;  inner  ,''p  much  thick- 
ened its  whole  extent. t 

Melanopsis  Lam.  General  form  of  Melania;  but  the 
spire  shorter,  and  the  base  of  the  aperture  notched. 

Melafusus   Sw.       Sub-fusiform ;   the    base  contracted, 
and  the  aperture  and  spire  nearly  equal. 
1  Species,  America. 

Melanopsis  Lam.     Obovate  ;    the  base  obtuse  ;   io3  A 
spire  pointed,  acute  ;  inner  lip  greatly  thick- 
ened, particularly  at  its  upper  part,  and  in- 
ternally ;  suture  compressed  and  flattened, 
buccinoides  Lam.  {fig.  103.) 

Melanithes  Sw.     Habit  of  Melania  ;  but  the  spire  is 
obtuse,  and  the  suture  prominent. 
Ferus.  Moll.  Melanop.  pi.  2.  f.  1 1, 12,  13.,  pi.  1.  f.  5.  7.  16. 

*  I  suspect  that  the  true  distinction  of  this  second  type  oi  Melania  will 
rest  on  tlie  deciduous  nature  of  the  spire. 

+  This  type,  which  represents  Planaxis,  unites  on  the  other  side  to  Me- 
lacantha.    I  have  a  small  species,  but  know  not  whether  it  is  described., 

z  3 


342  SHELLS    AND    SHELL-FISH.  PART  II. 

Canthidomus  Sw.  Spire  generally  short ;  whorls  co- 
ronated with  spines,  or  marked  with  longitudinal  ribs; 
base  obtuse. 

F^rus.  Moll.  Melanop.  pi.  2.     costata.  Sow.  Gen.  f.  3. 
f.  9.  10.,pl.  1.  13,14,15. 

Melatoma   Sw.       Fusiform  ;    longitudinally 
ribbed ;  a  deep   sinus   at  the  top   of  the 
outer  lip  ;  base  contracted,  channel  wide.* 
M.  costata  Sw.  {Jig.  104.) 

Cerithidea.  Clavate  ;  cerithiform  ;  aper- 
ture sub-emarginate. 

Triphorus  Desh.  Shell  small,  slender,  sub- 
cylindrical  ;  spire  long,  of  numerous 
whorls  ;  aperture  sinistral ;  outer  lip  re- 
flected over  and  united  to  the  inner,  but 
leaving  a  circular  opening. 

T.  costata.  Sow.  Gen.  f.  375. 

Cerithidea  Sw.    Shell  light ;  decollated ;  outer  lip  semi- 
circular,  dilated    by   a    flattened    border ;    aperture 
emarginate. 
C.  lineolata.   Griff.  Cuv.  14.  f.  4.         fragilis,  lb.  32.  f.  12. 

Ceriphasia  Sw.  Cerithiform  ;  outer  lip  thin,  dilated  at 
the  base  ;  aperture  small,  slightly  emarginate,  without 
any  internal  groove  ;  inner  lip  thin. 

C.  sulcata  Sw.  (Jig.  38.  p.  204.) 

Planaxis.  Animal  marine  ;  shell  obovate  ;  inner  lip 
much  thickened  above  ;  pUlar  flattened ;  the  base 
with  a  small  notch  or  sinus. 

P.  semisulcatus  Lam.     Sow.  Gen.  f.  3. 

SuB-FAM.     TURBIN.E. 

Animal  marine  ;  shell  solid,  spiral ;   aperture  round  or 
oval,  entire,  sometimes  toothed.t 

*  Representing  P/^M>-o<owrt,  and  united  to  Melafusus. 
f  Except  certain  types  of  Me/ampus,  which  appear  amphibious  ;  and 
others  which  have  plaits  and  teeth  on  the  aperture. 


PART  II.  TURBINE.  343 

ScALARiA  Lam,      Shell  turreted,  marked  with  longi- 
tudinal ribs  ;  aperture  circular,  entire, 
pretiosa.     En.  Meth.  481.  f.  1. 

TuRRiTELLA.      Shell    turreted ;     spire   subulate_,  very 

long ;  umbilicus  none. 
Rissoa  Fremonville.       Spire  moderate,   perpendicular, 

acute ;  outer  lip  thickened ;  aperture  oval. 
R.  reticulata.    Sow.  Man.  346. 

Turritella  Lam.  Aperture  round,  entire  ;  outer  lip  thin. 
T.  duplicata.     En.  Meth.  449.  f.  1. 

Eulima  Desh.    Shell  smooth,  polished  ;  spire  distorted, 
acute ;  outer  lip  thin,  dilated  in  the  middle. 
E.  labiosa.   Sow.  Man.  f.  347.  marmorata.  lb.  f.  348. 

Pyramidella  Lam.  Shell  smooth,  polished ;  outer  lip 
thin  ;  base  of  the  pillar  produced,  and  marked  with 
distinct  plaits. 

P.  terebellum.   Sow.  Man.  f.  342. 

Truncatella  Risso.       Cylindrical ;  turreted  ;  the  apex 

very  obtuse  ;  aperture  oval,  small,  entire  ;  the  lips 

united. 

T.  leevigata  Risso.     Drap.         costulata.    Zool.  111.    pi.  13. 
pi.  1.  f.  31.  f.  13—18. 

Turbo  Linn.*     Shell  turbinate  ;  spire  short,  generally 
pointed,   not  longer   than    the    aperture ;    inner  lip 
flattened,  broad, 
littoreus  (the  common  winkle).  Sow,  Man.  363.  {fig.  109.  e.) 

Tornatelldf  Lam.   Animal  marine  ;  shell  solid ;  body- 
whorl  cylindrical ;  spire  pyramidical,  pointed  ;  aper- 
ture contracted  above;  effuse  beneath  ;  base  of  the 
pillar  with  two  strong  plaits  ;  outer  lip  very  thin. 
T.  fasciata.    En.  Meth.  452.  f.  3. 

Melampus.     Amphibious  Volutes,     Obovate,  or  oval ; 
the  spire  generally  short,  and  never  longer  than  the 

*  Tuba,  Assimt'nea,  and  Monatifrma,  which  may  probably  be  sub-genera, 
lam  not  acquainted  with :  and,  as  their  animals  appear  unknown,  I  am 
fearful  of  locating  them  incorrectly. 

f  This  sub-genus  possibly  unites  Turbo  to  Melatnpus  ;  it  is  the  only  one 
which  has  that  sort  of  colouring  peculiar  to  marine  shells. 

z  4 


344  SHELLS    AND    SHELL-FISH.  PART  II. 

aperture ;  outer  lip  thin,  but  thickened  on  the  in- 
ternal margin  ;  one  or  both  lips  with  distinct  teeth 
or  plaits ;  animal  with  two  tentacula,  sessile  eyes, 
but  no  operculum. 

Geovula  Sw.     Oval ;  spire  very   short,  tur-      ^^^'' 

binated,    cancellated,    of    many    whorls ;  ff^'^s. 

apex  obtuse  :  outer  lip   thickened   inter-  wM'-'MV\ 

nally;  inner  lip  with  a  strong  plait  near  p-JW    Mi 

the  base.  (Jig.  105.)  |\v#  ml  1 

G.  Midje.    Griff:  Cuv.  27.  f.  8.  W  J^i  / 

Pedipes  Adans.       Shell   small,    turbinate   or      \  i£/  J 
sub-spiral ;  body-whorl  ventricose  ;  aper-        ^£1/ 
ture  on  both  sides  defended  by  several  teeth  and  plaits. 
P.  afra.    Lowe,  in  Zool.  Journ,  v.  pi.  12.  f.  8 — 12. 

Scarabus  Montf.  Shell  depressed  ;  spire  as  long  as  the 
aperture ;  umbilicus  partly  open ;  both  lips  with 
plaits,  and  tuberculous  teeth. 

S.  imbrium.  Sow.  Man.  f.  299. 

Melampus  Montf.      Oval,    sub-coniform ;     spire    very 
short,  obtuse  ;  aperture  narrow  ;  inner  lip  thin,  and 
striated  internally  ;  pillar  plaited, 
fasciatus.  Gr.  Cuv.  27.  f.  13.      exxguns  Lew.  Z.  J.  v.  12.  f.  6,7. 

Rhodostoma  Sw.  General  form  of  Melampus  and 
Tornatella  ;  but  the  aperture  is  not  striated,  and  the 
inner  margin  of  the  lip  is  broad,  considerably  thick- 
ened, and  distinctly  notched  towards  the  top. 

coffea.    Chem.  120.  f.  1043.        nucleus.    Fer.  Tab.  Sys.  105. 
fabula.  Fer. Tab.  S>s.  1 05.  24.  26. 

ScissuRELLA  J)'Or&?^,  Shell  very  small  or  minute;  he- 
liciform  ;  spire  depressed  ;  aperture  effuse  ;  outer  lip 
with  a  narrow  fissure  or  slit ;  umbilicus  open. 

S.  elatior.     Sow.  Man.  f.  340. 

Family  NATICID^. 

Shell  globose,  generally  smooth  ;  spire  minute,  scarcely 
raised ;  aperture  large,  semicircular. 


PART  II.  NATICIN^.  345 

SuB-FAM.   1.     NATICINiE.      Sea  Snails. 

Shell  globose ;  *  inner  lip  smooth^  not  depressed. 

Natica  Lam.  Operculum  shelly  ;  shell  globose ; 
ventricose  ;  umbilicus  open^  with  a  central  gibbous 
ridge,  or  prominence. 

N.  lineata.      Mart.     186.    f.      millepunctata.      lb.    186.    f. 
1864,  1865.  1862,  1863. 

Naticella  Guild.  Operculum  horny  _;  shell  globose, 
but  generally  depressed ;  umbilicus  nearly  filled  up 
with  a  vitreous  deposition  of  the  inner  lip  ;  spire  ob- 
tuse. 

?  N.  aurantia.     Mart.  189.  f.  1934,  1935. 

Glohularia  Sw.-j-     Shell  not  depressed,  but  the  aperture 

very  effuse  ;  base  of  the  body-whorl 

with   a   thickened  belt;   apex  of  the        "" 

spire  acute  ;  recent   and   fossil,   {^fig, 

106.) 

sigaretina  Lajn.    Coq.  Foss.  13.  f,  1. 

patula.  lb.  f.  2. 

depressa.  lb.  f.  3. 

acuminata.    lb.  f.  4.  spirata.     Coq.  Foss.  13.  f.  7, 

fluctuata.    Griff.  Cuv.  1.  f.  4.     crossitana.    lb.  f.  8. 

Mamillaria  Sw.   Shell  oval,   heavy  ;  spire  very  small, 

pointed ;  inner  lip  considerably  thickened  at  the  top, 

and  filling  up  a  large  umbilicus,  placed  near  the  base 

of  the  aperture  ;  aperture  effuse. 

M.  lactea  Sw.      Mart.     189.     tumida  Sw.    lb.  189.  f.  1928 
f.  1922,  1923.  —1931. 

Sigaretus  Auct.      Oval,    flattened,    ear- shaped ;    inner 
lip  almost  wanting ;  umbilicus  none. 

T.  concavus.    Lam.   Hist.  Nat.  vi.  2.  p.  208. 

*  The  arrangement  of  this  group,  from  ignorance  of  the  animals  of  the 
major  part,  is  purely  artificial,  being  founde    cnly  on  the  shells. 
t  Globulus  Sow. :  altered,  th:.   the  specific  names  may  not  be  changed. 


34<6 


SHELLS    AND    SHELL-FISH.  PART  II. 


Naticaria  Sw.*    Oval ;  convex  above  ; 

umbilicus   small,  open,   placed   very 

near  the  top  of  the  aperture ;   inner 

lip  reflected^  small,  {^fig.  107.) 

N.  melanostoma.  Mart,  189.  f.  1926, 1927. 
cancellata   Sw.      lb.    189.  f.  1939. 
bifasciata.    GrifF.  Cuv.  1.  f.  2. 

Lacuna  Turton.  Turbinate  ;  thin ;  spire  very  small, 
of  two  whorls ;  the  general  shape 
is  like  JVatica,  but  the  base  is 
contracted;  umbilicus  close  to 
the  top  of  the  aperture,  with  a 
groove  running  on  the  margin  of  the  pillar,  which  is 
oblique ;  operculum  horny  ;  aperture  effuse,  semicir- 
cular. (Jig.  108.) 

L.  ^aWidula  Turton.  (fig.  108.) 

Leucotis  Sw.  Form  of  the  shell  intermediate  between 
Sigaretus  and  Lacuna  ;  but  there  is  no  pillar ;  umbi- 
licus large,,  pervious  ;  inner  lip  thin^  slightly  reflected 
at  the  top  I  surface  sculptured. 

Sigaretus  cancellatus.     Lam.   Sys.  vi.  2.  p.  207.      Chem. 
165.  f.  1596.  1597, 

SuB-FAM.  ?     NERITINiE.     Nerits. 

Globose ;  spire  very  small ;  pillar  oblique  ;  inner  lip 
very  broad,  depressed,  more  or  less  flattened,  and  gene- 
rally toothed  ;  aperture  semicircular. 

Nerita  Linn,  Shell  solid ;  inner  lip  toothed  or  gra- 
nulated. 

N.  peloronta.     Mart.  192.  f.     pollta.      Mart.  193.  f.  2002, 
1977—1981.  2003. 

Neritopsis  Gray.  Aperture  sub-orbicular ;  pillar  lip 
thickened  above  and  below,  with  a  wide  notch  in  the 
middle,  f 

N.  granosa.      Sow.  Man.  f.  331. 

♦  These  are  probably  aberrant  species,  connecting  Sigaretus  with  Ma- 
millaria;  but,  until  the  whole  are  better  understood,  I  think  it  advisable 
they  should  be  kept  distinct. 

t  Apparently  related,  by  the  shell,  to  Leucotis. 


PART  II, 


TROCHID^. 


34.7 


Neritina  Lam,  General  shape  of  Nerita ;  but  the 
outer  lip  is  thin  and  smooth,  the  inner  one  rather 
convex  and  crenated  ;  surface  smooth. 

N.  meleagris.      Chem.  124.   f.  1088.  a — i. 

Clitlion  Montf.  Leach.  General  shape  of  Neritina; 
but  there  is  an  obtuse  lobe  on  the  inner  lip,  the 
outer  is  dilated  at  its  origin,  and  the  whorls  are  armed 
with  spires. 

C.  corona.      Chem.  124.  f.  1083,  1084. 

Velotes  Mont.  Nearly  orbicular ;  depressed ;  above 
convex ;  beneath  flat ;  spire  nearly  obsolete ;  inner 
lip  toothed,  as  large  as  the  aperture,  which  is  semi- 
circular. 

V.  perversa.     Sow.  Man.  f.  326. 

Pileolus  Cookson.  Shell  above  patelHform  ;  spire  in- 
ternal ;  aperture  beneath  small,  semilunar;  outer  lip 
margined ;  inner  crenated. 

P.  plicatus.      Sow.  Man.  f.  332. 

Naviceila  Lam.    Somewhat  patelliform  ;  oval ;  convex 
above ;  flat  beneath  ;  aperture  large  ;  inner  hp  nar- 
row, thin,  assuming  the  form  of  a  plate  across  one 
end  of  the  under  surface  ;  operculum  shelly.  * 
N.  elliptica.     Sow.  Man.  f.  323. 


Family  TROCHID^. 

109  ,^^  c  d 


*  Unites  the  Naticidts  to  the  Haliotidce,  by  Crepidula. 


348 


SHELLS    AND    SHELL-FISH, 


PART  II. 


Shell  turbinate,  mostly  trochiform  *,  the  substance  almost 
always  perlaceous  ;  outer  lip  never  thickened  ;  aperture 
entire,  closed  by  a  shelly  or  horny  operculum. 


SuB-FAM.    SENECTIN^.      Snake  Shells. 

Operculum  round ;  calcareous ;  shell  turbinate ;  the 
basal  whorl  ventricose ;  pillar  always  smooth  ;  aperture 
round,  rarely  oblique. 

^ENECTvs Humph.  Imperforate;  the  base 
produced  into  a  broad  flat  lobe  ;  spire 
rather  elevated  and  pointed ;  the 
whorls  convex ;  aperture  perfectly 
round ;  not  more  oblique  than  Helix  ; 
inner  lip  entirely  wanting,  {fig.  110.) 


imperialis.  Mart.  1 80.  f.  1 7  90. 
marmoratus.  E.  M.  448.  f.  1. 
pethiolatus.  Mart.  f.  1777-8. 
cornutus.  lb.  179.  f.  1779-80. 
setosus.  En.  Meth.  448.  f.  4. 
argyrostomus.  Mart.  f.  1766. 
chrysostomus.  lb.  f.  1766. 


radiatus.    Mart.  f.  1788-9. 
margaritaceus.  lb.  f.  1762. 
Sprenglerianus.  lb.  f.  1801-2. 
crenulatus.  lb.  f.  1811-12. 
hippocastanum.  lb.  f.  1807-10 
coronatus.  En.  M.  448.  f.  2. 
angulatus  Sw.  Sow.  Gen.  f.  8. 


Marmarostoma  Sw.  Umbilicus  deep ;  spire  of  few 
whorls,  much  depressed,  and  obtuse;  inner  lip  ob- 
solete ;  base  even  more  produced  than  in  Senectus, 
but  never  distinctly  channeled. 

M.  versicolor.      Mart.    176.      undulata.       Chem.     169.     f. 
f.  1740,  1741.  1640,  1641. 

Delphinula  Lam.  Turbinate  ;  spire  depressed,  the  tip 
obtuse  ;  pillar  almost  entirely  wanting  ;  the  umbili- 
cus being  large  and  pervious ;  exterior  of  the  shell 
rough  with  tubercles  or  lamellar  plates,  (^fig.  IO9.  h.) 

torquata.  Mart.  Conch. 2.f. 71.     laciniata.     En.    Meth.    451. 
lamellosa.  Zool.  J.  v.  p.  331.  f.  1. 

CYCLOGANTHAt  Sw.     Sub- depressed,  trochiforra ;    im- 

*  Except  Phasianella. 

t  Resembles   Tuhicanthus,  but  the  aperture  is  hardly  perlaceous,  the 
body-whorl  not  flattened  beneath,  or  the  mouth  oblique. 


PART  II.  TROCHIN\(E.  349 

perforate ;  both  sides  compressed ;  substance  of  the 
shell  not  perlaceous,  but  convex ;  mouth  slightly  ob- 
lique ;  lips  united ;  base  not  produced  :  doubtful  type, 
stellaris.  Mart.  164.  f.  1553-4.     calcar.  En.  M^th.  451.  f.  2. 

CiDARis  Sw.  Perlaceous  ;  turbinate  ;  generally  smooth  ; 
the  base  not  produced;  the  inner  Hp  not  concave; 
always  imperforate  ;  aperture  round,  but  oblique  ; 
operculum  very  thick  :   representing  Calliostomus. 

sarmaticus.         Mart.       179.  pethiolatus.      Mart.    183.    f. 

f.  1777,   1778.  1826. 

smaragdus.  En.  M.  448.  f.  3.  pictus  Sw.     En.  Meth.  448. 

E.  coronatus.  5*2^.  Chem.  165.  f.  5. 

f.  1585,  1586.  ater  Sw.*  Sow.  Gen.  f.  7. 

SuB-FAM.    TROCHINiE.      Trochus,  or  Top. 

Shell  trochiform ;  the  body-whorl  more  or  less  wide^ 
and  flattened  beneath;  the  spire  conical  or  pyramidical; 
aperture  oval,  wider  than  it  is  high ;  operculum  horny,  t 

Canthorbis.  Operculum  shelly;  aperture  very  oblique, 
broad_,  and  narrow  ;  the  basal  whorl  much  flattened ; 
pillar,  in  the  typical  examples,  twisted :  representing 
Cei'ithium. 

Tuhicanthus  Sw.     Turbinate;    aperture    oval,    effuse; 

very  oblique ;    inner  lip  broad,  concave,  spreading, 

united  to  the  outer  lip ;  base  of  the  pillar  simple, 

blended  with  the  circumference  of  the  aperture.  :|: 

rugosus.         Mart.     180.     f.      Tuber.     Mart.  165.   f.  1373. 

1782—1785.  Cookii.      lb.  163.  f.  1540. 

ceelatus.    lb.  162.  f.  1536.  imbricatus.    Id.  162.  f.  1531. 

Canthorbis  Sw.    Suns.     Nearly  disk-shaped :   spire  but 
slightly  raised ;  the  margin  of  the  body-whorl  flat- 
tened, and  serrated  with  flat  spines ;  inner  lip  united 
to  the  outer ;  pillar  and  aperture  as  in  the  last. 
C.  imperialis.   Mart.  173.  f.  1714. 


*  Is  this  the  Turbo lugubr is?  Zool.  Journ.  v.  345. 

f  Except  in  the  first  genus,  which  connects  this  sub-family  and  the 
Senectin/e,  and  in  T.  Niloticus  (as  it  is  said),  which  connects  Canthorbis 
with  Trochus. 

X  Connected  to  Cidaris  by  C.  rugosus. 


350  SHELLS    AND    SHELL-FISH.  PART  II. 

Pyramidea  Sw.  Imperforate ;  spire  much  elevated, 
pyramidical,  acute ;  basal  whorl  beneath  much  flat- 
tened, and  scarcely  convex ;  pillar  spiral,  the  base 
very  short,  turning  inwards,  and  then  outwards,  but 
smooth ;  outer  lip  thin ;  inner  wanting.*  (^fig.  IO9.  c.) 
obalisca.         Mart.      160.     f.      Nilotica.  Mart.  168.  f.  1614. 

1511,  1512.  virgata.  lb.  160.  f.  1514. 

foveolata  Gm.     Mart.  161.  f.     marmorata.  lb.  167.  f.  1606. 
1516,  1517.  Mauritiana.  lb.  163.  f.  1547. 

Lamprostoma  Sw.  Umbilicated ;  pyramidical,  spire 
elevated,  acute  ;  basal  whorl  much  flattened  beneath, 
slightly  convex  ;  pillar  spiral ;  the  base  short,  and 
marked  by  distinct  plaits  ;  aperture  striated  ;  inner 
lip  wanting. 

L.  maculata.   Mart.  168.  f.  1515,  1516. 

Carinidea  Sw.  Imperforate  ;  spire  pyramidical,  acute; 
basal  whorl  concave  beneath,  and  carinated  round  its 
circumference  ;  aperture  oval,  entire,  slightly  angu- 
lated  at  the  base  of  the  pillar,  which  turns  inwards. 

C.  concavus.     Mart.  168.  f.      brevisplnus.  ?       Sow.     Gen. 
1620,  1621.  (Turbo.)  f.  1. 

Trochus  Linn.  Operculum  horny  ;  shell  trochiform  ; 
the  basal  whorl  broad ;  aperture  oval ;  sometimes  an- 
gulated  by  the  union  of  the  pillar  and  the  outer  lip, 
but  rarely  toothed  or  striated.f 

Chlorostoma  Sw.  Deeply  umbilicated  almost  to  the 
top  of  the  spire  ;  inner  lip  forming  a  semi-margin  to 
the  umbilicus  ;  outer  lip  angulated  at  the  base,  with 
one  or  two  tubercles  ;  body-whorl  almost  flat  be- 
neath, and  nearly  carinated  at  its  edge  ;  aperture 
remarkably  oblique  :  representing  Monilea.X 

C.  argyrostoma.    Mart.  165.  f.  1362,  1363. 
umbilicaris.   lb.  171.  f.  1666. 

*  Troch.  Niloticus  is  probably  esculent  between  this  and  Lamprostoma  ; 
but  I  have  not  seen  a  thorouglily  full-grown  specimen,  with  the  mouth 
quite  formed  :  the  operculum  is  said  to  be  horny ;  but  this  may  be 
doubted. 

f  Except  in  Trochidon,  which  represents  Monodonta  Lam.  in  this  circle. 

%  Troch.  mcrula  Lam.  connects  this  sub-genus  with  Pa^odella. 


PART  II.  TROCHIN^.       ]  351 

Trochus  Linn.  Umbilicus  either  very  open  or  small^ 
but  always  apparent ;  base  of  the  outer  ^^^^^^ 
lip  sinuated  where  it  unites  with  the  ^^^^SfJ^ 
pillar ;  inner  lip  generally  spreading^  ^K\t"^^S^!) 
flattened,  and  concave  ;  body-whorl  ^^^^^^ 
convex  beneath,  rounded  on  the  sides  ;  \(^£<x^ 
aperture  obliquely  round ;  spire  short,  \^^^^^ 

depressed,  pointed,     (^fig.  111.)  lU  ^■^-^_/ 

T.  pica.    Mart.  176.  f.  1750.     cinerarius   Linn.  Mart.  171. 
magus.    lb.  171.  f.  1656.  f.  1686. 

Pagodella  Sw.  Trochiform  ;  generally  thin,  and  always 
not  perlaceous  ;  aperture  and  pillar  perfectly  united 
and  entire  ;  operculum  horny. 

P.  major.  Mart.  163.  f.  1541,  1542. 
tectum-persica.    lb.  f.  1543,  1544. 

Trochidon  Sw.  Trochiform  ;  spire  more  elevated  than 
in  the  last;  but  the  base  of  the  pillar  either  angulated, 
umbilicus  none,  or  forming  a  tooth  more  or  less  deve- 
loped, often  with  a  lateral,  depressed  groove,  but  no 
umbilicus ;  margin  of  the  outer  lip  thin,  the  inside 
rarely  striated,    {fig.  IO9.  d.) 

T.  labeo.      En.    Meth.   447.     viridis.    lb.  447.  f  2. 
f.  1.  canalifera.      lb.  f.  5. 

Calliostoma  Sw.  Imperforate  :  spire  elevated,  acute ; 
aperture  broader  than  high,  transversely  ovate,  hardly 
sinuated  at  the  base,  and  slightly  oblique;  shells 
always  smooth,  and  often  polished :  representing 
Cidaris. 

zizyphina.  Pen.  Zool.  pi.  80.  annulata.  Ch.  165.  f.  1551-2. 

f.  103.  doliata.  lb.  f.  1579 — 1583. 

conuloides.     Lara.    No.  47.  granatina.      Mart.     170.     f. 
conula.  Mart.  166.  f.  1588.  1654,  1655. 

erythroleuca.Ib.l62.f,1529.  Australis.  Zool.  Jour.  v.  331. 

MoNODONTA  Lam.  Base  of  the  piUar  forming  a  distinct 
tooth  ;  umbilicus  deep*,  with  a  deep  groove  below  ; 
aperture  striated ;  outer  lip  not  thin  at  the  margin. 

Elenchus  Humph.     Shell  smooth ;    spire    considerably 

*  Except  in  Elenchus  and  Echinidea. 


352  SHELLS    AND    SHELL-FISH.  PART  II. 

lengthened;  body -whorl  comparatively  smaller  ;  base 
of  the  pillar  with  a  slight  angle,  or  an  obsolete  tooth  ; 
aperture  smooth,  very  brilliant;  passing  into  Calli- 
ostomus. 

E.  Iris.     Mart.  161.  f.  1652,     splendidulus.  Sw.  Sp.  Nov.* 
1653.  {fig.  109.  a.) 

Echinella  Sw.     Shell  imperforate,  granulated,   not  per- 
laceous  ;  spire  considerably  lengthened;  pyramidical ; 
base  of  the   pillar  with    a    distinct    tooth ;  aperture 
striated :   representing  Pagodella. 
E.  granulata.     Sw.  Sp.  Nov.     coronaria.  En.Meth.447.  f.6. 

Monodonta  Lam.  Turbinated ;  in  general  umbilicated, 
having  a  groove  below,  and  a  tooth  at  the  base  of  the 
pillar ;  aperture  nearly  round,  striated  within  ;  um- 
bilicus never  toothed ;  representing  Senecus  and  Tro- 
chidon. 

M.  retusa.     En.  Meth.  447.  f.  4. 

Fragella  Sw.  Trochiform ;  umbilicus  deep,  always 
open,  and  toothed  round  its  margin  ;  base  of  the 
pillar  twisted,  and  forming  a  tooth -like  process  at  its 
tip  :  representing  Trochidon. 

Pharaonis.  En.  M.  447.  f.  7.      Sowerbyana.  Stv.  Sow.  Gen. 
undata.      lb.  447.  f.  3.  f.  9.  11.     (  Trochus.) 

Monilea  Sw.  Umbilicus  deep  and  wide,  but  the  edges 
quite  smooth,  with  a  thickened  half  margin,  formed 
by  the  inner  lip,  which  terminates  abruptly  ;  base  of 
the  outer  lip  with  one  or  two  tubercles,  or  obsolete 
teeth ;  margin  of  the  whorls  concave ;  inner  lip 
often  striated  :  representing  Chlorostoma. 
M.  callifera  ?     Lam.  Sys.  27.  No.  59. 

Solarium  Lam.     Shell  nearly^discoid,  not  perlaceous  ; 
spire  none  ;  aperture  angulated,  smooth  within  ;  the 
edge  acute  ;  the  lips  wanting,   {fig.  109-  i,  k.) 
S.  perspectivum.       En.  Meth.  446.  f.  1. 

Onustus  Humph.  Shell  trochiform  ;  the  surface  irre- 
gular,   and    often    covered    with    extraneous    bodies 

*  Small,  entirely  fawn  colour,  or  light  brown  ;  aperture  of  the  most 
brilliant  purple  and  emerald  green.      Australia. 


PART  II. 


ROTELLIN^. 


353 


cemented  and  incorporated  with  the  calcareous  sub- 
stance of  the  shell ;  the  under  part  of  the  body-whorl 
flattened  or  concave,  umbilicate. 

O.  Solaris.      Mart.  173.  f.  1700,  1701. 
Indicus.      lb.  172.  f.  1697,  1698. 

SuB-FAM.     ROTELLIN^. 

Substance    perlaceous ;     shell    depressed^  smooth,    and 
highly  polished  ;  mouth  thin  ;  umbilicus  closed.* 

Chrysostoma  Sw.  Shell  turbinate ; 
the  whorls  few  and  convex ; 
aperture  effuse,  round ;  inner 
lip  thickened,  just  over  and 
almost  concealing  the  umbilicus. 
Nicobaricus.      Mart.  182.  f.  1822-1825.       (Jig.  109.) 

RoTELLA  Lam.  Shell  flattened,  nearly  discoid,  polished  ; 
inner  lip  very  thick,  and  spreading  over  half  of  the 
under  surface  ;  aperture  small,  angulated ;  operculum 
horny.    {Jig.  lOQ. f,g.) 

R.  lineotata  Lam.      Mart.  166.  f.  1601.  e,  f,  g 

Thelidomus    Sw.    {Jig.  113.)       Turbi-      ^^^^  ii3 
nate,  sub-trochiform  ;  umbilicus  large,         '^"     '* 
open ;  the  whole  shell  entirely   com- 
posed of  grains  of  sand. 

Braziliensis  Sw.  {Jig.  113.) 

SuB-FAM.     PLEUROTOMARI^. 

Trochiform ;  the  aperture  with  a  slit  or 
fissure.     Fossil  only. 

Pleurotomaria  Defrance.  Spire  more  or  less  elevated. 
Being  only  found  in  an  imperfect  or  fossil  state,  nothing 
has  been  determined  as  to  the  umbilicus,  substance, 
operculum,  &c. 

P.  reticulata.      Sow.  Gen.  1.  i. 


J  1 


*  These  have  probably  no  operculum,  and  Rotella  may  be  an  internal 
shell. 

A    A 


354  SHELLS    AND    SHELL-FISH.  PART  II. 


SuB-FAM.     PHASIANELLIN^. 

Obovate^  spiral,  polished ;  aperture  oval ;  spire   longer 
tharij  or  equal  to,  the  aperture ;  operculum  shelly. 

Phasianella  Lam.     Umbilicus  none,      {fig-  IO9.  h.) 
P.  bulimoides.    En.  Meth.  449.  f.  1 .  a—c. 


Family  HALIOTID^.    The  Ear-Shells. 

Shell  disk-shaped  entire  ;  the  spire  nearly  obsolete,  de- 
pressed, convolute,  mostly  lateral,  and  of  only  two  or  three 
minute  whorls  ;  pillar  none  ;  operculum  none. 

Haliotis  Linn.  Iridescent ;  ear-shaped  ;  a  row  of  per- 
forated holes  on  the  thickest  side  of  the  aperture. 
The  sub-genera  remain  to  be  determined. 

Stomatia  Lam.     Oval  or  oblong ;  the  shell  resembling 
Haliotis,  but  without  perforations. 
The  types  of  form  are  enumerated  at  page  232. 

('ALYPTRiEA  Lam.  Shell  not  perlaceous  ;  patelliform, 
but  with  the  first  rudiments  of  an  internal  support, 
and  often  of  a  spire. 

Bicatillus  Sw.  Shell  patelliform  ;  spire  or  whorls 
none ;  a  cup-shaped  appendage  within,  more  or  less 
complete 

B.  extinctorium  Sw.    Sow.  Gen.  f,  3.      deformis.  lb.  f.  1. 

CalyptrcEa  Lam.  Patelliform  ;  internal  appendage  half 
funnel-shaped,  but  open  in  front. 

C.  equestris  Lam.    Sow.  Man.  f.  2.34.  Sow.  Gen.  f.  2. 

Haliotidea  Sw.     Spire  prominent,  formed  of  two  whorls, 
and  placed  laterally  ;  umbilicus  open, 
sigaretoides.  *  Sic.     dilatata  ?  Sow.  Gen.  f.  9.  (Cali/ptrcpa.) 


*  This  sub-genus  seems  to  form,  with  certain  VetuUnce,  the  passage  to 
our  Chelinotus,  or  the  Sigarcti  of  authors. 


PART  II.  CHELINOTUS. SCUTIBBANCHIA.  355 

TrochiUa  Sw.     Shell  conical,  patelliform  ;  spire  central, 

of  two  or  more  whorls  ;  umbilicus  closed. 
T.  auriculata.  Sow.  Man.  f.  236.  pileus.  lb.  f.  237,  238. 

Biconia  Sw.     Patelliform,  conical ;   internal  appendage 
forming   a   funnel-shaped  fold,   not   open  in  front ; 
apex  central,  sometimes  with  the  vestige  of  a  whorl. 
Humph.  Conch,  f.  11.  and  12. 

Chelinotus  Sw.  Animal  cheloniform,  broad ;  de- 
pressed ;  the  mantle  much  larger  than  the  shell, 
lobed  in  front ;  tentacula  two,  short,  obtuse ;  eyes 
basal ;  mouth  circular  ;  shell  ear-shaped,  thin,  fragile, 
imperforate ;  pillar  none. 

Velutina  Lam.  Animal  —  }  fragile  ;  shell  with  the  two 
spiral  whorls  raised,  so  as  to  resemble  a  Lymnia;  no 
pillar ;  epidermis  thin,  horny. 

laevigata.      Sow.  Man.  f.  337. 

Chelinotus  Sw.  Shell  thin,  diaphanous,  white,  entirely 
concealed  in  the  back  of  the  animal,  which  is  marked 
with  hexagonal  partitions. 

Sigaret  de  Tonga.     Quoy,  Voy.  d' Astrolabe. 

Coriocella   Blainville.     Animal    broad    oval,    with    the 
anterior  lobes  not  prolonged,  or  the  back  divided  as 
in  the  last ;  shell  thin,  flexible,  membranaceous.* 
C.  niger  De  Blainville.      Man.  de  Malac.  pi.  42.  f.  1 . 

Crepidula  Lam.    Shell  boat-shaped;  the  apex  or  spire 
at  the  narrowest  extremity  :  half  of  the  internal  cavity 
covered  by  a  testaceous  plate. 
C.  fornicata.  Sow.  Gen.  f.  1.  aculata,  lb.  f.  5. 

Tribe  3.  SCUTIBRANCHIA.      The  Limpets. 

Shell  pateUiform  or  cup-shaped  ;  without  any  spire   or 
internal  support. 

Fissurella  Lamarck.  An  oval  aperture  at  the  apex, 
or  highest  part  of  the  shell. 

*  GrifF.  Cuv.  xii.  68. 
A   A    2 


556 


SHELLS    AND    SHELL-FISH.  PART  II. 


Fissurella.     Apex  nearly  central ;  aperture  large,  oval 
simple. 
F.  picta.    Sow.  Gen.  f.  1.  gigas.  Sw.  Sp.  Nov. 

MachrocMsma  Sw.  Aperture  very  large,  oblong,  placed 
closed  to  the  margin. 

M.  hiatula  Sw.     Sow.  Gen.  f.  5. 

Clypidella  Sw.  One  extremity  of  the  shell,  near  the 
perforation,  slightly  raised,  truncated,  and  sub-emar- 
ginate. 

C.  pustula.  Sow.  Gen.  f.  3. 

Fissuridea  Sw.     Sub-conical,  cap-shaped  ;   the  summit 
close  to  the  posterior  margin  ;  the  perforation  narrow. 
T.  pileus.   Sw.  Sp.  Nov. 

Emarginula  Lam.  Either  patelliform  or  cap-shaped  ; 
the  apex  near  the  posterior  end ;  the  anterior  margin 
or  summit  with  a  very  narrow  slit  or  fissure. 

Emarginula  Lam.  Cap-shaped ;  fissure  on  the  an- 
terior margin. 

E,  reticulata.    Sow.     Gen.        fissura.    Sow,  Man.  f.  241. 
f.  5.  elegans.  lb.  f.  4. 

Cemoria  Leach.  Cap-shaped ;  fissure  down  the  centre 
of  the  apex. 

C.  Flemingii.    Sow.  Man.  f.  244. 

Rimula  Def.  Cap-shaped  ;  fissure  long,  in  the  middle 
of  the  shell  ;  margin  entire. 

R.  Blainvillii.  Sow.  Gen.  f.  243. 

Parmophorus  Lam.     Patelliform  ;  fissure  assuming  the 
form    of  an  anterior  sinus,  scarcely  perceptible    on 
the  anterior  margin. 
P.  elongatus.    Sow.  Gen.  f.  1,     breviculus.    Sow.  Gen.  f.  2. 

Hemitoma  Sw.   Patelliform  ;  the  fissure  not  cut  through 
the  shell,  but  merely  forming  an  internal  groove. 
H.  tricostata  Sw.     Sow.  Gen.  f.  6. 

HipPONYX.       Shell   cap-shaped;    the  apex  sometimes 


PART  II.  CYCLOBRANCHIA.  357 

produced  and  slightly  curved  inwards  ;  muscular  im- 
pression semi-circular. 

Hipponyx  De  Fr.     Cap-shaped  or  patelliform  ;  strong  ; 
the  margins    thick_,  and  reposing  upon  a  thin,   flat- 
tened ;  testaceous  plate,  forming  a  second  valve, 
cornucopia.      Sow.  Man.  f.  199. 

P'deopsis  Lam.  Shell  cap-shaped ;  thin ;  the  apex 
much  produced  and  incurved  ;  no  basal  support  or 
internal  appendage. 

P.  Hungaricus.   Sow.  Man.  f.  240. 

Pedicularia    Sw.      Shell  irregular,    sub-patelliform  ; 
a  thick,  large,  obsolete  apex   on   one   of  the   longest 
sides,  and  an   internal   callous   rim  within,  on   one 
side  only  ;  circumference  undulated,  irregular. 
P.  Sicula  Sw.  {Jig.  44. ) 

Patella  Linn.  Shell  entire,  simple,  cup-shaped  or 
patelliform  ;  apex  pointed,  entire.* 

P.  miniata.    Sow.  Gen.  f.  2. 

Siphonaria  Sow.  One  side  more  dilated  than  the  other, 
and  marked  by  an  internal  groove. 

S.  Sipho.    Sow.  Gen.  f.  1. 


Tribe  4.  CYCLOBRANCFJIA.      The  Chitons. \ 

Animal  patelliform,  oval ;   the  mantle   coriaceous  ;  the 
back  covered  with  imbricate  shelly  plates  ;  no  tentacula. 

Chiton  Lin.  Back  with  large  transverse  plate  ;  zone, 
or  mantle,  wide,  covered  with  small  scales,  either 
imbricate  or  reticulate. 

C.  squamosus.      Sow.  Gen.  f.  2. 

Canthapleura   Guild.      Plates   as    in    Chiton ;    the 

*  The  fresh-water  genus  Ancylus  has  the  same  shaped  shell,  but  the 
animal  shows  it  belongs  to  the  Limnn'iancs. 

t  Not  having  analysed  this  tribe,  I  have  adopted  the  genera  and  arrange- 
ment of  Guilding,  see  Zool.  Journ.  xvii.  p.  27.,  especially  as  they  thus  form 
a  circular  group. 

A  A    3 


358  SHELLS    AND    SHELL-FISH.  PART  II. 

mantle  rough,  with  moveable  spines,  prickles,  setace- 
ous hairs,  or  granules. 

C.  spinosus.      Sow.  Gen.  f.  1. 

Phakellopleura  Guild.  Plates  moderate  ;  the  mantle 
ornamented  with  a  single  series  of  tufts  of  radiating 
hairs. 

P.  fascicularis.      Sow.  Gen.  f.  3. 

Chitonellus  Lam.     Body  larvseform  ;     plates  small, 
detached ;  mantle  naked  ;  sides  with  punctures,  re- 
sembling spiracles. 
C.  larviformis  Burrows,     latus  Guild.     Z.  J.  xvii.  p.  78. 

Cryptoconchus  Blainv.  Plates  moderate,  entirely  co- 
vered with  the  soft  down  of  the  zone,  each  plate 
having  two  lateral  and  tabular  pores,  and  four  on  the 
anterior  plate. 

C.  porosus  Burrows. 

Tribe  5.     TECTIBRANCHIA.      The  Sea  Slugs. 

Body  naked  ;  branchia  generally  covered  by  a  coriaceous 
or  testaceous  plate,  or  oviform  shell,  which  is  more  or 
less  concealed  in  the  mantle,  or  its  lobes ;  eyes  sessile, 
minute. 

SuB-FAM.  1.     PHYLLIDINiE. 

Shell  none  ;  body  shaped  as  in  Chiton  ;  mantle  coria- 
ceous ;  branchia  folliculated,  placed  on  both  sides  of  the 
body,  under  the  edges  of  the  mantle ;  tentacula  small, 
short,  two  or  four. 

Phyllidea  Cuv.  Shape  oval  ;  tentacula  four,  the 
upper  pair  cylindrical  and  pointed,  the  under  very 
small,  inferior,  and  placed  on  the  side  of  a  small 
mouth. 

P.  pustulosa.      Riipp.  Atlas,  i.  pi.  7.  f.  1. 

Diphyllidea  Cuv.  Posterior  end  narrowed  ;  tentacula 
two,  the  inferior  pair  represented  by  two  tubercles. 

D.  lineata  Otto. 


PART  II.  APLYSIAN^.  359 


SuB-FAM.  2.      APLYSIANI^.     Sea  Hares. 

Mantle  dilated,  undulated  at  its  edges  and  thrown 
on  the  back  ;  branchia  dorsal,  pectinated,  generally 
covered  with  a  convex,  irregular,  horny,  or  calcareous 
plate ;  tentacula  two  or  four,  ear-shaped. 

Aplysia  Linn.     Animal  with  a  short  neck  ;  tentacula 
four,  the   upper  and   large  pair  flat,  and  folded  so  as 
to  resemble  the  ears   of  a  hare  ;  mantle  very  large, 
and  sufficiently  dilated  for  swimming, 
fasciata.  Rang.  Ap.  pi.  6,  7.      Argus.     Riipp.  Atl.  i.  pi.  7. 

Thallepus  Sw.  Body  more  slender  and  fusiform  ; 
the  lobes  of  the  mantle  short,  and  incapable  of  being 
used  for  swimming  ;  tentacula  two,  large,  ear-shaped  ; 
eyes  not  visible. 

T.  ornatus  Sw.      Sp,  Nov.      See  page  250. 

DoLABELLA  Lam.  Body  pyriform,  very  broad  behind  ; 
the  lobes  compactly  folded  on  a  hatched-shaped  cal- 
careous shell,  which  covers  the  branchia. 

D.  Rumphii  Lam.      Blainv.  Man.  pi.  43.  f.  5. 

BuRSATELLA  BMuv.  Body  nearly  globular;  the  dor- 
sal edges  of  the  mantle  united  together,  but  leaving 
a  short  opening  for  the  passage  of  the  water  to  the 
branchia,  which  have  no  covering. 

B.  Leachii  Blainv.     Man.  pi.  43.  f.  6. 

NoTARCHUs  Cuv.  Body  shaped  much  like  that  of  Aply- 
sia, covered  with  flat  palmated  lobes  or  membranes; 
tentacula  two,  large  and  palmated ;  mantle  and 
branchia  as  in  Bursatella. 

N.  laciniatus.      Riipp.  Atl.  i,  pi.  7.  f.  2. 

SuB-FAM.  3.    BULLING.     The  Bullas. 

Animal  without  apparent  tentacula  ;  body  oblong ;  both 
extremities  obtuse ;  eyes  vertical,  very  minute  ;  bran- 
chia dorsal,  covered  by  a  convolute  shell,  destitute  of 

A  A    4 


360 


SHELLS    AND    SHELL-FISH.  PART  II. 


any  spire  ;  the  base  widest :  this  in  the  typical  species, 
is  covered  by  the  lobes  of  the  mantle ;  in  others  the 
whole  animal  is  contained  in  the  shell.* 

BullcB  Lam.       Shell    internal,  oval,  colourless  ;    inner 
lip  thin  ;  apex  umbilicated ;  animal  oblong,  without 
tentacula. 
aperta.  Sow.  Man.  f.  248.       ?  Guildingii  Sw.  {See Jig.  46.) 

Bulla.  Animal  furnished  with  two  connected  bony 
plates ;  shell  obovate  ;  contracted  above,  and  effuse 
at  the  base. 

B,  Lignaria.  Sow.  Man,,  f.  251. 

Vesica  Sw.       Animal    unknown  ?     probably    contained 
within  the  shell ;    shell    oval,    solid ;    apex    umbi- 
licated ;  aperture  entire  ;    contracted  above, 
ampulla.  Sow.  Man.  f.  252.  Naucum.  Sow.  Man.  f.  250. 

Aplustra  Schum.    Animal }  shell  solid,  but  thin  ; 

furnished  with  a  distinct  but  depressed  spire. 
A.  fascidta.      Sow.  Man.  f.  249. 

Bullinula  Beck.  General  shape  of  the  last ;  but  the 
spire  is  slightly  produced  and  conic  :  a  doubtful 
type  } 

B.  lineata.   Sow.  Man.  f.  253. 

Vitrella  Sw.       Animal ?    shell  internal,    hyaline, 

or  sub-transparent ;  convolute  ;  the  apex  carinated  ; 
the  substance  elastic. 

V.  fragilis.    Sow.  Man.  f.  247. 

DoRiDiuM  Mecken.    Animal  with  the  lobes  dilated  into 
fin-like  processes,  but  without  a  shell. 
D.  carnosa.  Cuv.  Mem. 

SuB-FAM.  4.   GASTEROPTERID^. 

Gasteropteron  Meek.  Animal  short,  ovate,  natatorial ; 
the  margins  of  the  foot  dilated  into  broad  wing-like 

•  The  arrangement  of  this  sub-family,  founded  chiefly  upon  the  shell, 
is  purely  artificial,  no  knowledge  having  been  gained  of  the  greater  part  of 
the  animals.  Such  genera  as  Cryptellay  Sec,  founded  merely  upon  the 
branchial  covering  of  some  unknown  animal,  can  never  be  admitted  into 
Malacology. 


PART  II.  PLEUROBRANCHINiE.  S6l 

lobes  ;   shell  none  ;    branchia  naked,   placed  on  the 
right  side  of  the  body. 

G.  Meckelii.    Blainv.  Man.  de  Malacol.  pi.  45.  f.  3. 

SuB-FAM.  5.   PLEUROBRANCHIN^. 

Animal  cheloniform,  branchia  pectinated,  placed  on 
the  right  side  under  the  edge  of  the  mantle  which 
sometimes  covers  a  calcareous  shell. 

Umbrella  hsLxn.  Animal  large  and  circular;  anus  tu- 
bular, placed  behind  the  branchia;  tentacula  two, 
short,  as  in  the  next  genus  ;  with  eyes  at  the  in- 
ternal base,  between  which  is  a  proboscis.  Shell 
resembling  a  limpet ;  but  the  middle  is  thickest,  and 
the  edges  very  sharp. 

U.    Indica.    Blainv.  Man.  pi.  44.  f.  1. 

Pleurobranchus  Cuv.  Animal  cheloniform ;  body 
overlapped  by  the  mantle  and  the  foot ;  the  former 
sometimes  contains  a  small  oval  plate,  either  horny 
or  calcareous  ;  mouth  small,  probosciform ;  ten- 
tacula two,  tubular,  and  short, 
oitrinus.  Riipp.  Atl.  i.  5.  f.  1.      Forskalii.   lb.  pi  5.  f.  2. 

Pleurobranch^na  Meckel.  Anus  above  the  bran- 
chia ;  tentacula  four,  short,  remote ;  shell  none ; 
branchia  and  genital  orifices  as  in  the  last. 

Meckelii.      Leve.  Dissert.  Griff.  Cuv.  xii.  43. 


Order  DITHYRA.     Bivalve  Shells. 

Tribe  1.  TUBULIBRANCHIA  Cuv. 

Animal  inhabiting  a  tubular  shell  affixed  to  other  sub- 
stances and  somewhat  spiral  at  its  tip  ;  tail  turned  un- 
der the  body  and  terminated  by  a  thin  operculum ; 
head  obtuse,  with  two  short  tentacula  with  sessile  eyes  ; 
mouth  a  vertical  orifice  with  two  filaments  beneath  be- 
longing to  the  foot;  hermaphrodite.* 

*  The  animal  of  Magilis  being  unknown,  I  am  afraid  of  including  it  in 
this  group. 


362 


SHELLS    AND    SHELL-FISH. 


PART   II. 


Vermetus.      Shell  tubular,    contorted ;     the    terminal 
whorls  spiral. 

G.  lumbricalis.    Sow.  Man.  f.  345. 

Vermillia  Lam.     The  terminal  whorls  not  spiral. 
V.  triquetra.    Sow.  Man.  f.  7. 

Siliquaria  Brug.     Terminal  whorls  spiral ;  a  narrow 
punctured  fissure  on  one  side  of  the  shell. 
S.  anguina.    Sow.  Man.  f.  1. 

Tribe  2.     MACROTRACHI^. 

Animal  with  one  or  two  long  respiratory  siphons^  either 
distinct  or  united  ;  the  margins  often  furnished  with 
little  teeth. 

Family  1.     PHOLID^. 

Shell  bivalve,  sedentary,  generally  perforating,  opening 
at  one  or  both  ends ;  the  valves  often  prolonged  into  a 
shelly  tube,  sometimes  of  great  length  :  representing  the 
Tubulibranchia. 


11-1 


Aspergillium.  Animal  living  in  sand,  and  not  fixed 
on  or  upon  any  other  substance :  inhabiting  a  calca- 
reous tube. 

Aspergillium  Lam.     Shell  tubular,  nearly  straight,  one 


PART  II.  PHOLID^.  363 

extremity  open,  at  the  other  closed  by  a  plate  which 
is  perforated  with  small  holes,  near  to  which  are  the 
bosses  :   lives  in  sandy  shores.  {Jig.  1 J  4.  /^  g.) 

A.  vaginiferum  Lam.    Sow.  Gen.  f.  1.  2. 

Clavagella  Lam.     Two  irregular  valves  placed   within 
a  short  shelly  tube,  dilated  at  its  open  extremity,  and 
to  which  one  valve  is  fixed  or  soldered  at  the  other : 
perforates  stones,  &c.  (^fig.  114.  «,  A.) 
C.  aperta.    Sow.  Gen.  f.  1 — 4. 

Fistiilana  Lam.  Animal  not  perforating  ;  tube  purse- 
shaped,  straight,  the  narrow  extremity  open,  the  other 
closed;  a  transverse  septum  crosses  the  tube,  and 
incloses  at  its  largest  end  a  bivalve  shell,  which  is 
elongated,  solen-shaped,  gaping  widely  at  the  basal 
margin,  and  united  by  a  ligament,  i^fig.  114.  w.) 

F.  clava.   Sow.  Gen.  f.  1 — 4. 

Gastrochixa  Lam.  Animal  perforating  or  parasitic  ; 
tube  calcareous,  clavate,  nearly  divided  longitudinally 
for  half  its  length  by  an  internal  ridge,  which  forms 
a  double  aperture;  the  other  or  thick  extremity  en- 
closes an  ovate  bivalve  shell,  gaping  very  wide  ante- 
riorly ;  hinge  linear  and  marginal ;  teeth  none.  {^fig. 
114.  6,  c,d) 

G.  modiolina.    Sow.  Gen.  f.  1.* 

Pholadomya  Sow.    Shell  115 

not     tubular,      pholas- 
shaped,  perlaceous, 

slightly  gaping,  no  ac- 
cessary valves ;  ligament 
short ;     external    hinge 
with  a  small  elongated    pit   somewhat  triangular,  and 
a  marginal  plate  on  each  valve ;  umbones  very  close. 

P.  Candida.    Sow.  Gen.  Man.  f.  57.  {fig.  115.) 

Pholas  Linn.     Animal  perforating  but  not  tubular  ; 

*  I  consider  the  perforating  species  to  be  types  of  a  different  sub-genus  ; 
and  probably  those  which  are  parasitic  upon  other  shells  should  likewise  be 
separated. 


364 


SHELLS    AND    SHELL-FISH.  PART  II. 


shell  free^  oblong-ovate^   thin,  with  an  internal  com- 
pressed tooth  in  each  valve  and  accessary  pieces. 

Pholas  Linn.  Shell  gaping  at  both  extremities  over  the 
umbones  ;  ligament  none.  (^ Jig.  122.  f.) 

P.  dactylus.  Sow.  Gen.  f.  1. 

PholidcEa  Leach.  Resembling  Pholas,  but  the  anterior 
end  is  closed  by  a  thin  calcareous  prolongation  of  each 
valve,  and  the  posterior  end  has  a  cup-shaped  ap- 
pendage, {fig,  122.  g.) 

T.  papyracea.    Sow.  Gen.  f.  3.   Man.  f.  56. 

Martesia  Leach.  General  characters  of  Pholas,  but 
both  extremities  are  closed. 

M.  clavata  Auct.   (fig.  122.  ^. ) 

Xylophaga  Sow.  Habit  of  Pholas ;  but  the  shell  is 
orbicular,  widely  gaping  anteriorly,  and  with  ac- 
cessary valves ;  each  valve  with  an  incurved  tooth, 
and  an  internal  transverse  rib. 

dorsalis.  Sow.  Man.  f.  50,  51. 

Teredo  Linn.  Shell  tubular,  irregular ;  the  valves 
pholas- shaped,  short  and  nearly  orbicular. 

Teredo  Linn.  Valves  resembling  Xylophaga;  placed 
at  the  thickest  extremity  of  a  long,  irregular  tube, 
''  which  is  open  at  both  ends,  the  anterior  end  di- 
vided into  two  apertures  furnished  with  two  oper- 
cula."*  {fig.  114<.k,l.) 

T.  navalis.      Sow.  Gen.  Man.  f.  48,  49. 

Teredina.  Tube  clavate,  irregular,  nearly  divided  into 
two,  by  a  projection  on  each  side  within,  thus  form- 
ing a  double  opening  at  the  smallest  extremity; 
valves  as  in  Teredo,  but  wholly  external,  incrustated 
with  the  tube,  and  having  accessary  valves. 

T.  personata.      Sow.  Gen.  Man.  f.  46,  47.  {fig.  114.  i.) 


*  I  have  not  leisure  to  look  into  these  characters,  and  have  therefore 
adopted  Mr.  Sowerby's  account  of  this  and  the  next  genus. 


PART  II, 


M  Y  AD^. SOLENINjE. 


365 


Family  2.     MYAD^.      Gaping  Bivalves. 

Shells    regular^    always    with    defined    cardinal  teeth ; 
valves  more  or  less  gaping  at  one  or  both  extremities. 


SuB-FAM.     SOLENIN.E.      Salens. 

Shells  generally  linear,  and  always  open  at  both  extre- 
mities ;  cardinal  teeth  distinct. 

SoLEN  Linn.  Shell  very  straight,  broad,  linear,  and  of 
equal  length  throughout ;  umbones  very  small,  ter- 
minal ;  cardinal  teeth  small ;  ligament  long,  exter- 
nal. 

truncatus.  Sow.  Gen.  f.  1.        vagina.  lb.  f.  2.  (Jiff.  116.  b.) 

Ensatella  Sw.     Shell  slightly  curved. 

E.  Eiu'opea  Stv.     {Solen  Ensis  Auct. ) 

NovAcuLiNA  Benson.  Straight,  of  equal  length 
throughout ;  the  extremities  rounded ;  umbones 
towards  the  middle  ;  cardinal  teeth  ^ ;  dorsal  margin 
slightly  thickened. 

N.  Gangetica.      Sow.  Man.  f.  63. 


366 


SHELLS    AND    SHELL-FISH.  PART  II. 


Lepton  Turton.  Small,  nearly  round  ;  umbones  cen- 
tral ;   teeth ?   The  cardiform  type. 

L.  squamosus.      Sow.  Man.  f.  62. 

SoLENocuRTis.  Shell  depressed,  thin,  transverse,  oblong 
ovate ;  the  valves  slightly  gaping  at  one  extremity  ; 
cardinal  teeth  and  umbones  nearly  central. 

Solenella    Sow^.     Oval,  compressed  ;  epidermis  glossy  ; 
hinge  margin  nearly  straight;   cardinal  teeth  wanting  ; 
posterior  lateral  teeth  numerous,  sharp ;  anterior  end 
somewhat  truncated  :  representing  Nucula. 
S.  Norisii.      Sow.  Man.  f.  138. 

Solenocurtis    Blainv.       Oblong-ovate,     nearly    linear ; 
umbones  small,  nearly  central,  with  a  thickened  in- 
ternal  transverse    ridge;     ligamental   margin    much 
thickened,   (^fig,  ll6.  e.) 
S.  radiata.      Sow.  Man.  f.  61.   Blainv.  Man.  pi.  80.  f.  1. 

Sanguinolaria  Lam.  Ovate,  compressed ;  posterior 
end  sub-rostrated  ;  anterior  rounded ;  cardinal  teeth 
small,  %.  {fig.  Il6.  d.) 

S.  rosea.      Sow.  Man.  f.  98. 

Glauconome  Gray.*  Obovate,  not  gaping,  sub-ventri- 
cose,  and  rounded  anteriorly,  narrowed  and  com- 
pressed posteriorly  ;  cardinal  teeth  ^,  some  of  which 
are  bifid ;  ligament  oblong ;  external  epidermis  ex- 
tending over  the  margin  ;  fluviatile  :  apparently  re- 
presenting Mactra  in  this  genus, 

G.  chinensis  Gray.  Sow.  Man.  f.  64. 

Solenymia  Lam.  Shape  of  Solenocurtis,  but  some- 
what cylindrical  ;  umbones  very  small,  and  placed 
laterally  ;  hinge  margin  straight ;  valves  gaping  on 
their  anterior  end ;  cardinal  teeth  i,  dilated  and 
compressed,  with  a  callous  ridge  between  ;   ligament 

*  I  have  not  seen  this  shell,  which,  from  the  figure  quoted,  has  exactly 
the  shape  of  Unio  uvala. 


PART  II. 


SOLENIN^. MY  A. 


367 


internal   and   external :    representing    Pandora    and 
Glycymeris.     Epidermis  thin,  shining,  dilated. 
S.  Mediterranea.      Sow.  Gen.  f.  112.  (/^.  116.  a.) 

My  A  Linn.  Shell  thick,  ventricose,  ovate,  transverse, 
one  end  truncated  and  gaping  ;  umbones  generally 
nearly  central  and  prominent ;  cardinal  tooth  gene- 
rally large  ,•  spatulate  valves  often  gaping. 

117 


Anatina  Lam.  Hyaline,  thin  ;  cardinal  tooth  spoon- 
shaped,  sometimes  with  a  transverse  internal  append- 
age, or  plate,  like  an  additional  tooth,     (^fig.  11 6./.) 

M.  subrostrata.    En.  M^th.  228.  f.  3. 

Mya  Linn.     Shell  thick,   strong  ;  cardinal  tooth  spatu- 
late ;  both  extremities  gaping  * ;  cardinal  teeth  ^. 
M.  truncata.     En.  Meth.  229.  f.  2.      {fig.  117.  h,c.) 

Panopia  Lam.  Resembling  Mya ;  cardinal  teeth  -i, 
acute ;  ligamental  margin  greatly  thickened  ;  liga- 
ment external.     (/(/,  ll6.  c.) 

P.  Aldrovandi.  Sow.  Man.  f.  65. 

Corhula.     Inequivalve,    ovate ;    umbones    central,   one 
more  prominent  than  the  other  ;  valves  not  gaping ; 
cardinal   teeth  \,  bearing   the   ligament :  leading  to 
Mactra.     (117.  e,/.) 
'Sulcata.    En.  Meth.  230.  f.  1.      C.  nucleus.  Sow.  Man.  89. 

*  Connected  to  Anatina  by  Anaiina  rupicola  Lam, 


368 


SHELLS    AND    SHELL-FISH. 


PART  II* 


Pandora  Lam.   Inequivalve,  thin,  rostrated,  perlaceousj 

one  valve  flat,  the  other  convex  ;  ligament  internal ; 

umbones  small;  cardinal  teeth  5,  lamellar,  sagittate,  or 

like  aV  reversed:  connected  to  ^na^ma.(^^.  1  l'7.g,h.) 

P.  rostrata.  En.  Meth.  251.  f.  1. 

Mactra  Linn.  Equivalve  ;  the  valves  slightly  gaping 
on  one  side  ;  ligament  internal  and  external ;  cardi- 
nal teeth  complicated. 

Lutraria  Lam.    Shell  thin,  transversely  oval  or  oblong; 
cardinal  teeth  ^,  angular,  followed  by  a  spoon-shaped 
lobe   containing   the   cartilage ;    lateral    teeth    none. 
(^^.  118.  &.) 
L.  compressa.  En.  M.  257.  f.  4.     papyracea.  Sow,  Gen.  f.  2. 

Mactra  Linn.*  Transversely  oval  or  sub-trigonal ;  um- 
bones prominent ;  cardinal   teeth  %,  angular,  some- 


times with  additional  laminte  ;  cartilage  entirely  in- 
ternal, nearly  central;  lateral  teeth  i.     {fig.  118.  c.) 

Neapolitana.     roll.   Test,      stultorum.   En.  M.  265.  f.  2. 
pi.  18.   f.  1—5.  turgida.  Sow.  Gen.  f.  2. 

Schizodesma  Gray.     General  character  of  Mactra  ;  but 

*  Including  Mactra  bicolor,  &c.,  Auct. 


PART  II.  MACROTRACHIA.  —  TRLLIiVID^.  36^ 

the  umbones  are  remote ;  the  ligament  placed  in  an 
external  slit ;  the  lateral  teeth  very  short  and  small, 
and  the  cardinal  teeth  nearly  obsolete. 

S.  Sprengleri.     En.  Meth.  252.  f.  3. 

Hemimactra  Sw.  General  form  of  Mactra  ;  but  the 
cardinal  teeth  entirely  wanting ;  cartilage  internal, 
central,  in  a  large  triangular  cavity  ;  lateral  teeth  \, 
distinct,  lamellar,  striated  :  connected  to  the  Glycu- 
neri. 
H.  gigantea.  Lam.  v.  472.  No.  1.     grandis  Sw.  Sp.  Nov. 

Crassatella  Lam.  Shell  solid,  heavy,  not  gaping,  more 
or  less  rostrated  ;  hinge  very  thick  ;  cardinal  teeth  |- 
sub-angTilar,  striated,  and  placed  on  one  side ;  imme- 
diately beneath  the  umbones  is  a  triangular  cartilage; 
lateral  teeth  obsolete:  representing  Pa  wrfora,  Trigonia, 
Placuna,  Szc. 
C  Kingicola  Lam  {fig.  1 18.  a.)     rostrata.  Sow.  Man.  f.  84. 

Glycimeris  Lam.  Oblong,  transverse ;  both  extre- 
mities gaping ;  cardinal  and  lateral  teeth  entirely 
wanting ;  but  the  hinge  margin  very  thick  ;  ligament 
large,  external :  representing  Solenimya,  and  con- 
nected to  Solen  by  Novaculina.* 

G.  Siliqua.    Sow.  Gen,      {fig.  118.  6,  c.) 

Family  TELLINIDiE.     Solid  and  dose  Bivalves. 

Shell  never  gaping  t ;  equivalve  ;  the  margins  thickened 
and  solid  ;  rarely  covered  with  an  epidermis ;  cardinal 
and  lateral  teeth  well  developed. 

SUB-FAM.  1.      CYCLING. 

Animal  generally  fluviatile  ;  shells  covered  by  an  epi- 
dermis. 

CyclasJ  Lam.     Shell  thin,  transversely  ovate,  equila- 

*  The  four  other  sub-genera  are  unknown.        f  Except  in  Psammobia. 
X  Including  PisiduTn. 

B  B 


570 


SHELLS    AND    SHELL-FISH. 


PART  II. 


teral ;    cardinal  teeth   small;    lateral   teeth    ^^  long, 
compressed;  ligament  external,   {fig.  II9.  &.) 
C.  rivicola.    Sow.  Man.  f.  111. 


Cyrena  Lam.     Shell  thick,  transversely  ovate,  nearly 
equilateral ;   cardinal  teeth  4- ;  lateral  teeth  4,  short, 
thick,  obtuse  ;  fluviatile  and  marine.   {fig.W^.n.^ 
C.  Siimatrensis.    Sow.  Gen.  1 — 4. 

Megadesma  Bowdich.*      Shell  thick,    trigonal,    nearly 
equilateral ;  cardinal  teeth  4t  ',  lateral  teeth  obsolete  ; 
hinge  very  thick  ;   ligament  external.  (^fig.llQ.  d.) 
M.  radiata.    Sow.  Man.  f.  115. 

Gnathodon  Gray.  Shell  transversely  obovate,  in- 
equilateral ;  bosses  thick,  prominent,  remote ;  car- 
dinal teeth  i  ;  lateral  ",  ;  cartilage  internal,  placed 
by  the  side  of  the  cardinal  teeth. 

G.  cuneatus.    Sow.  Man.  f.  83. 

CuMiNGiA    Sow.       Shell    transversely   obovate ;    hinge 
with  a  spatulate  cavity  filled  by  the  cartilage ;  car- 
dinal teeth  \,  very  small ;  lateral  teeth  -| ;  marine  : 
leading  to  Erycina,  and  representing  Amphidesma. 
C.  mutica.    Sow.  Man.  f.  87. 

EBYCiNAf  Lam.      Shell    always    transverse,   generally 

cuneate,  but  rarely  equilateral  ;  both  valves  closing  ; 

cardinal   teeth  ^,  between  which   is   the   ligament ; 

lateral  teeth  ^y  one  of  which  is  lengthened. 

striata.    Sow.   Gen.  f.  2.  plebeja.    lb.  f.  3. 

(/5r.  118.  d,e.) 

*  Gttlathcea  of  Lam. 

t  This  name  should  be  chanjjed,  havinjj  been  previously  applied  by 
Fabricius  to  a  large  family  of  lepidopterous  insects.  Eiijx  may  be  used,  a& 
preserving  the  same  mythological  idea. 


PART  II.  MACROTROCHIA. TELLININ^.  371 

SuB-FAM.     TELLININ^. 

Animal  marine ;    the  siphons  excessively  long.     Shell 
rather  thin^  more  or  less  compressed  ;  bosses  small. 

PsAMMOBiA.*  Lam.  (fg.llS.i.)  Shell  transverse,  oval 
or  oblong,  angulated,  gapingatone  or  both  ends  ; 
ligament  external ;   cardinal  teeth  -|, 

rugosa  Sow,  Chem.  9.  f.  79 — 82.  ferroensis.  Penn.  47.  f.  31. 
vespertina.  Chem,  7.  f.  59.    Poll,  i.  pi.  15.  f.  19. 

Tellina  Linn.  Shell  transverse,  greatly  compressed, 
nearly  equilateral ;  the  valves  on  the  inferior  liga- 
mental,  or  anterior  side,  sinuated  and  angulated ; 
cardinal  teeth  |^,  or  -| ;  lateral  teeth  -2,  remote  from 
the  cardinal,  (fig.  120.  a.) 
radiata.  En.  Meth.  289.  f.  3.  latirostra.  Zool.  17.  I.  pi.  20. 

Ltjcina  Lam.  Shell  generally  round  or  orbicular, 
equilateral,  the  outer  surface  sculptured ;  ligament 
external ;  cardinal  and  lateral  teeth  distinct,  but  va- 
riable in  their  number  ;  anterior  muscular  impression 
very  long  and  narrow,  (fig.  120,  c.) 
L.  punctata.    Sow.    Gen.  f.  1.       Pennsylvanica.  f.  4. 

UnguUna  f  Lam.  Shell  irregularly  orbicular ;  bosses 
central ;  cardinal  teeth  -i,  bifid  ;  lateral  teeth  none ; 
ligament  both  internal  and  external ;  impression  of 
the  mantle  entire. 

transversa  Lam.     Sow.   Man,  f.  88.   {fig.  117.  d.  ) 

Amphidesma  Lam.    Shell  resembling  Lucina  in  shape; 
the  posterior  side   sometimes   flexuose,   and   slightly 
gaping;  cardinal  teeth  ^  or  %,  with  a  cartilige  between  ; 
ligament  external. 
A.  variegata.  En.  Meth.  291,  f.  3.     lucinalis.  lb.  286,  f. 

LoRiPEs  Poli.  Shell  orbicular,  equilateral ;  cardinal, 
teeth  obsolete  ;  lateral  teeth  none, 

L.  lactea,  Poli,  i.  pi,  25,  f,  28,  29. 

*  Representing  the  So/ens. 

f  JJngulina  Lam.  seems  to  be  merely  an  aberrant  Lucin&. 

B  E    2 


372 


SHELLS    AND    SHELL-FISfll. 


T-ART  H- 


SuB-FAM.   VENERINyE. 

Animal  with  the  two  siphons  shorter,  and  sometimes 
united  ;  shell  thick,  strong,  and  ventricose ;  bosses  pro- 
minent. 


c^> 


CoRBis  Lam.  Shell  transversely  roundish ;  bosses  curved 
in  different  directions  ;  cardinal  teeth  ^ ;  lateral  re- 
mote, short,  -|. 

C.  fimbriata.  Sow.  Gen.   {fg.  120.  h,i.) 

Venus  Z/mw.  Animal  with  the  two  siphons  shorter  than 
its  shell ;  shell  nearly  round,  or  oval ;  lateral  teeth 
close  to  the  cardinal  teeth,  4  ,  lateral  teeth  approxi- 
mate, and  diverging  from  the  summit  of  the  bosses  ; 
surface  often  rough,  {fig.  119-  ^0 
V.  purpura.  En.  Meth.  278.  f.  1 .         rugosa.  lb.  27S.  f.  4. 

Crassina  Lam.*  Shell  solid,  suborbicular;  bosses  nearly 
central.  Cardinal  teeth  4?  unequal  in  one  valve ; 
lateral  teeth  none. 

C.  Danmoniensis.  {fig.  120.  e.) 

*  The  other  subgenera  of  Tellina,  Venus,  Cytherea,  and  Dotiax,  are  not 
■worked  out. 


i»ART  II.  MACROTRACHIA. VENERINiE.  37^ 

CvTHEREA  Lam.     Animal    with    the   siphons   entirely 
united  ;    foot  large,    tongue-shaped  ;   shell  generally 
smooth  and  glossy  ;  cardinal  teeth  4  ;  lateral  tooth  \, 
placed  on  the  anterior  side.  (^  Jig .'19,0.  d,  y.) 
C.  Chione.  Poll.  ii.  pi.  20.  f.  1 .    niaculata.  En.  Meth,  265.  f.  4. 

DoNAx  Linn.  Shell  cuneate,  or  wedge-shaped,  the  an- 
terior side  very  short  and  truncate  ;  teeth  variable  in 
the  sub-genera,  (^jig.  120.  A.) 

D.  scorotum.       En.  Meth.  260.  f.  2. 

Capsa  Lam.     Shell  transverse,  nearly  equilateral ;   car- 
dinal teeth  -^  ;  lateral  teeth  ^  ;  ligament  external. 
C.  Braziliensis.  Sow.  Gen.  f.  1.  {fig.  120./".) 

Cardissa  Sw.  Shell  heart-shaped,  excessively  com- 
pressed ;  the  anterior  side  truncate,  and  often  concave  ; 
the  posterior  rounded. 

spinosa  Sw.   En.  Meth.  293.  f.  3. 

Cardium  Linn.  Shell  ventricose,  cordate,  or  longitudi- 
nally oval  ;  umbones  prominent;  cardinal  teeth  -| ; 
lateral  teeth  ^,  remote. 

Cardium  Linn.  Shell  ventricose,  equilateral ;  cordate,  with 
costated  ribs ;   often  armed  with  spines.      Typical. 

costatuni.    Wood,  General  Conch,     edula.  Wood,  Conch. 

i.  pi.  56.  f.  1.  pi.  55.  f.  4. 

tuberculatum,  Sow.  G.  f.  3- 

Lcevicardium  Sw.  Shell  longitudinally  oval,  inequila- 
teral, the  surface  neither  ribbed  nor  spired.  Sub- 
typical. 

Europeum.  Wood,    Con.  pi.     flavum.     Wood,  pi.  54.  £  2. 

54.  f.  1.  oblongum.    lb.  55.  f.  1. 

citrinum.  lb.  54.  f.  3.  ^olicum.  lb.  51.  f.  1. 


Hemicardium  Sw.  Half  heart-shaped  ;  the  anterior  side 
abruptly  truncated,  and  very  short :  representing 
Donux,  &c. 

H.  unedo.  Wood,  Conch,  pi.     fragrum.     Wood,  Conch,  pi. 
58.  f.  3.  58.  f.  1,  2. 

retusum.     lb.  58.  f.  4,  5.     lasvum  Sw.    lb.  57.  £  7,  8, 

B  B   3 


374>  SHELLS    AND    SHELL-FISH.  PART  II. 

Acardo  Sw.    Hinge  almost  without  teeth :  representing 
the  SaocacavidcE. 

Card,  edentulum.     Auct. 

Papyridea  Sw.    Shell  heart-shaped,  or  transversely  oval; 

inequilateral ;  the  anterior  side  almost  always  gaping  * 

representing  the  Pholidce. 

P.    Soleniforme.  Wood,     transversum.      Sow.     Conch- 

Conch,  pi.  56.  f.  3.  f.  4.  * 

ai^ertum.  lb.  56.  f.  2,  ringens.  Wood,  pi.  53.  f.  1,  2. 

Family  CHAMIDiE. 

Animal  marine  ;  shell  often  attached,  irregular,  not  per- 
laceous,  with  or  without  short  siphons  ;  lateral  teeth  on 
the  posterior  side  of  the  shell  only ;  cardinal  teeth  variable. 

Hippopus  Lam.     Cuneate  ;  both  valves  closed  ;  bosses 
nearly   central ;  cardinal  teeth  small ;    lateral    teeth 
long,  posterior. 
C.  maculatus.    Sow.  Gen.  f.  1.      En.  Meth.  236.  f.  2. 

Pleurorynchus   Phillips.     Anterior  end  abruptly  trun- 
cate, as  in  Hemicardium  ;  the  hinge  margin  elongated 
into  earlike  processes.     Fossil  only, 
elongatum.  Sow.  Min.  Con.       avicularis.   Sow.  Gen.  f.  2. 

Chama  Linn.     Shell  irregular,  attached  by  the  lower 
valve  ;  a  single  lengtliened  tooth  in  one  valve,  and  a 
corresponding  groove  in  the  other. 
C.  Damaecornis.  Sow.  Gen.  f.  1 .      arcinella.  Sow.  Gen.  f.  2. 

Isocardia  Lam.  Shell  heart  shaped,  regular,  ventricose  ; 
bosses  remote,  receding,  turbinate ;  cardinal  teeth 
lamellar. 

I.  cor.  En.  Meth.  232.  f.  1. 

Tridacna  Lam.     Animal  affixed  by  a  byssus,  which 
passes  through  a  large  opening  on  the  anterior  side ; 
cardinal  teeth  -|. 
glgas.  En.  M6th.  235.  f.  1.         elongata.  Sow.  Man.  f.  51. 

*  This  species,  by  uniting  Papyridea  and  Cardium,  completes  the  circu- 
lar succession  of  the  sub-generic  types. 


PART  II. 


MACROTUACHIA. 


SAXICAVlDiE. 


375 


Cleidoth(P7'us  Stuchbury.      Shell  resembling   Chama,  but 
somewhat  pearly  ;   hinge  with   an    "  internal,  testa- 
'ceous,  curved  appendage,"  inserted  in   a   depression 
within  each  of  the  bosses. 

C.  chamoides.  Sow.  Man.  f.  75. 

Diceras  Lam.  Somewhat  resembling  Isocardia ;  but 
the  bosses  are  excessively  produced  and  turned  dif- 
ferent ways.      Fossil  only. 

D.  arietinum.      Sow.  Gen.   f.  1. 

Myochama  *  Stuchbury.     Shell  irregular,   smooth,  at- 
tached by  the  lower  valve  ;  umbones  central ;  cardinal 
teeth  small,  -,  between  Avhich  is   an  internal   shelly 
appendage,  attached  to  a  horny  cartilage. 
M.  anomiodes.      Sov/.  Man.  f.  73. 

Cardita  t  Lam.  Shell 
free,  cardiform,  or 
sub-transverse,  rib- 
bed ;  cardinal  teeth 
^  or  ^,  lateral  1 ;  re- 
presenting Cardium. 
{fig.  121.) 

C.  sulcatus.  Sow.  Gen.  f.  3.      imbricatus.      lb.  f.  4. 
calyculatus.      lb.  f.  1,2.     oblonga.      lb. 


FA3IILY   SAXICAVID^. 

Animal  perforating  ;  shell  often  irregular  ;  lateral  teeth 

none  ',  cardinal  teeth  variable  or  obsolete. 

Saxicava  Lam.     Shell     transversely   oval,    irregular, 

gaping  at  one  or  both  ends ;  ligament  external ;  teeth 

obsolete,  {fig.  122.  a,  e.) 

S.  rugosa.      Sow.  Gen.  f.  1 — 4. 

Fetricola  Lam.      Shell  transversely  oval  or  oblong  ;  the 

valves  gaping ;  cardinal  teeth   variable,   but  always 

present ;  lateral  teeth  none  {fig.  122.   b,  c,  d.) 

P.  dactylus.      Sow.  Gen.  f.  3.     ochroleuca.    lb.  f.  4.  (6.) 

*  Affinities  uncertain. 

f  Including  Venericordia  and  Cypricardia  Lara.  ifig.  121.),  the  latter 
seems  an  aberrant  Cardita.  passing  into  Coralliophaga. 

B  B    4 


37.6" 


SHELLS    AND    SHELL-FISH. 


PART    II. 


CoralUophaga  Blainv.  Transversely  cylindrical ;  the 
bosses  placed  close  to  the  anterior  margin  ;  cardinal 
teeth  ^,  one  being  bifid  ;  lateral  teeth  obsolete.  A 
doubtful  type^  but  connected  to  Cardita. 

C.  carditoidea.     Sow.  Man.  f.  92. 

Thracia  Leach.*  Shell  transversely  oval^  posterior  side 
truncate  ;  bosses  central ;  lateral  hinge  margin  thick- 
ened ;  ligament  external ;  no  teeth  }  ;  affinities  and 
rank  uncertain. 

T.  corbuloidea.  Sow.  Man.  f.  93. 

Galeomma  Turton.^"  Thin^  oval^  equilateral ;  the  ven- 
tral margin  considerably  gaping ;  cardinal  teeth  ^  ; 
ligament  internal  and  external. 

G.  Turtoni.    Sow.  Gen.  f  1 — 3.      Maiiritiana.    lb.  f.  4,  5. 

Venerupes  ij:  Lam.  Animal  perforating,  analogous  to 
that  of  the  Solejis  ;  shell  transverse  ;  the  anterior  side 


*  I  have  not  seen  this  shell ;  the  figure,  but  not  the  definition,  being  in 
So\verl)y's  Mnnual.  Splnciiiii,  'J'urton,  seetns  to  be  an  aberrant  species  of 
Saxicava,  with  the  thickened  liinjie  margin  of  Thracia. 

f  Passes  into  Gastrochie/ia,  luul  thus  completes  the  circle  of  this  tribe. 

t  Judiciously  contracted  from  J't'nrn'riipfs.  These  perforating  animals 
have  no  connection  whatever  with  Pullastra.     See  Poli,  vol.  ii. 


PART   II. 


UNIONID^.  UNIONIW^. 


377 


very   short,  the   posterior    gaping ;   cardinal  teeth  ^ 
or  -I,  small  and  nearly  parallel ;  ligament  external. 
V.  irus.      Poll,  i.  pi.  10.  f.  1,2.  ;  and  ii.  pi.  19.  f.  25,  26.   . 

Tribe  3.    ATRACHIA. 
Animal  without  siphons. 

Family   1.    UNIONID^^.     River  Muscles,  or  Uriios. 

Animal  fluviatile ;  shell  solid,  perlaceous  ;  generally  with 
cardinal  and  lateral  teeth. 


I   * 
/ 


SuB-FAM.    1.      UNTONIN.E. 

One  valve,  with  two  cardinal  and  tw^o  lateral  teeth  ;  car- 
dinal teeth  short ;  the  mnbones,  or  bosses,  smooth  or 
longitudinally  undulated. 

Unio  Lam.    Cardinal  teeth  short,  oblique,  receding  from 
the  anterior  margin  of  the  shell,     {^jig,  123.  //.) 

JJnio.     Oval  or  round,  but  never  wdnged  _;  bosses  very 
prominent  j   cardinal  teeth  very  thick. 

U.  Mytiloides  Rafinesque.  sulcata.       Lea.  Am.  Tr.  iii. 
circula.     Lea.  Am.  Tr.  pi.  8.  f.  12. 

iii.    pi.  9.  14.  cornuta  Barnes. 
torsa  Rafinesque. 


378  SHELLS    AND    SHELL-FISH.  PART  II. 

Cunicula  Sw.  Ovate  oblong  ;  bosses  thick,  but  de- 
pressed ;   cardinal  teeth  moderate. 

C.  planulata.       Lea.     Am.  rubiginosa.     lb.  pi.  8.  f.  10. 

Tr.  iii.  pi.  9.  f.  13.  secura.      lb.  pi.  2.  f.l7. 

patula.      lb.      p.         f.  purpurascens.       Lam.  vi.  1. 

20.  p.  73. 

Ligumia  Sw.  Very  long  and  pod-shaped  ;  bosses  de- 
pressed ;  cardinal  teeth  moderate. 

S.  recta.    Lam.  vi.  1.  p.  74. 

Theliderma  Sw.     Posterior  hinge  margin  elevated  and 

winged  ;  surface  of  the  valves  tuberculated ;  cardinal 

and  lateral  teeth  perfect. 

T.  metanerva  Raf.  nodulosa  Wood.  Gen.  Conch, 

lachrymosa  Lea.  verrucosa  Barnes. 

pustulosa  Lea.  Peruviana  Lam.    En.  Meth, 
irrorata  Lea.  248.  f.  7. 

Megadomus  Sw.  Only  one  lateral  tooth  in  each  valve ; 
cardinal  teeth  two  ;  posterior  hinge  margin  winged. 

M.  gigas  Sw. 

Mglia  Sw.  Shell  generally  cuneate;  bosses  moderate  ; 
cardinal  teeth  short,  compressed,  diverging  towards 
the  anterior  margin. 

JEglia  Sw.     Shell  cuneate  ;  bosses  prominent ;  cardinal 
teeth  much  compressed,  placed  on  one  side   of  the 
bosses. 
M.  ovata   Saij.       Occidens  Lea.    Am.  Tr.  iii.  pi.  10. 

Naidea  Sw.  Shell  ovate  ;  bosses  depressed  ;  cardinal 
teeth  short,  thick,  obtuse,  placed  immediately  beneath 
the  bosses. 

N.  ater  Lea.  Am.  Tr.  iii.  pi.  7. 

Canthyria  Sw.  Shell  ovate  ;  cardinal  teeth  long,  com- 
pressed ;  surface  of  the  shell  spinous. 

C.  spinosa  (  U.  spinosa  Lea).    Syn.  frontisp. 

Mysca    Turton.    Shell  elongated,   oblong-ovate ;    car- 


PART  II.  ATRACHIA.  —  HYRIAN^.  379 

dinal  teeth  compressed  and  crenated;  the  outer  sharp^ 
and  almost  parallel  with  the  anterior  margin. 
M.    pictorum  *    LinJi.    En.       Batava  Larn.  En,  Meth.  248. 
Meth.  248.  f.  4.  f.  3. 

ovata  SiL\  {Jig.  56.)  '      '"  marginalis,  lb.  247.  f.  1. 

Potomida  Sw.     Oval ;  cardinal  teeth  short,   thick,  the 

outer  one  diverging  towards  the  anterior  margin. 

P.  sinuata  Za?w,  En.  Meth.      corrugata  Sw.  (fig.  51.) 

pi.  248.  f.  a,  h.  littoralis.  En.  M.  248.  f.  2. 

Lymnadea  Sw.     Posterior  hinge  margin  elevated  and 

winged ;  the  valves  connate  ;  the  surface  smooth. 

L.  alata     Sw.    Ex.    Conch.     ?  compressa  Lea.  Am.  Tr.  iii. 
{fig.  48.)  pi.  12.  f.  22. 

fragilis  Sw.    Zool.  111. 

SuB-FAM.   2.   HYRIANiE. 

Bosses  longitudinally  sulcated ;  cardinal  teeth  long,  com- 
pressed, placed  on  one  side  of  the  bosses  ;  hinge  margin 
winged,  {^fig.  123.  g.) 

Iridea  Siv.  Oblong  ovate  ;  bosses  small,  depressed, 
sulcated ;  inner  cardinal  tooth  placed  beneath  the 
outer. 

I.  granosa  Lmji.  En.  Meth.  248.  f.  9.t 

Castalia  Lam.  Oval  or  trigonal,  nearly  equilateral ; 
bosses  prominent ;  cardinal  teeth  short,  thick  ;  the 
outer  largest  and  crested. 

Naia  Sw.  Oval ;  cardinal  teeth  beneath  the  bosses, 
and  deeply  sulcated. 

C.     corrugata   Lam.        En.      picta   Sw.     En.    Meth.   248. 
Meth.  248.  f.  8.  f.  6. 

Castalia  Lam.     Trigonal,  nearly  heart-shaped. 

C.  cordata  ^  Sw.    Sow.  Man,     pectinata    SpLv.   Braz.   Test, 
f.  140.  pi.  25.  f.  3,  4. 

*  And  of  all  the  British  writers  who  have  not  confounded  it  with  the 
British  Ovata,  as  Lamarck  has  done. 

f  This  is  not  a  typical  species,  but  it  is  the  only  one,  out  of  tenor  twelve, 
which  I  believe  is  figured. 

J  Castalia  amhigua  Lam.  A  name  quite  inadmissible  to  a  decided 
species  ;  it  is  the  Cordata  of  Humphrey, 


380 


SHELLS    AND    SHELL-FISH. 


PAKT  II. 


Hyria  Lam.  Hinge  margin  straight ;  both  extre- 
mities elevated  and  winged ;  cardinal  teeth  very 
long,  and  resembling  lateral  teeth.   {ji(j,  124.) 

syrmatophora   Gmelin,  3222.    corrugata.  En.  Meth.  pi.  247. 
elongata    ^«;.       Ex.     Conch.  f.  2. 

pi.  24. 


HvridellaSw.  Transversely  oval;  bosses  not  sulcated; 
posterior  margin  elevated  and  winged  ;  one  cardinal 
and  one  lateral  tooth  in  each  valve. 

H.  australis.    Lam.  Sys.  vi.  1.  p.  80. 

SUB-FAM.  3.    IRIDININ^. 

Narrow  and  greatly  elongated  ;  hinge  margin  without 
teeth,  but  sometimes  granulated,  {fig.  123.  e,  f.) 

Iridina  Lam.      Hinge  margin  granulated. 

I.  striata  Sw.   Monog.    En.      ovata  Sio.  Monog. 

Meth.  204.  bisl.*  elongata  5'o<f.  (^private plate). 

Calliscapha  Sw.     Hinge  margin  smooth. 

C.  Nilotica  Sow.     Zool.  Journ.  i.  pi.  2. 

Mycetopus  D'  Orb.  Pod-shaped ;  hinge  margin  straight, 
smooth ;  the  extremities  obtusely  rounded,  or  sub- 
truncated  ;  considerably  gaping  ;  animal  perforating 

Solenoides,   Sow.  Man.  f.  \5l. 


*  The  figure  reinesents  this  as  an  "arcuate"  shell,  very  diifereiU  from 
that  figured  by  the  late  Mr.  Sowerby. 


PART   II.  ATRACHIA. ANODONTINiE.  381 


SuB-FAM.  4.     ANODONTINiE. 

Cardinal  teeth  none ;  lateral  tooth  extending  along  the 
hinge  or  entirely  wanting ;  hinge  margin  generally 
winged. 

Lamproscapha  Sw.  Shell  not  winged,  elongate  pod- 
shaped  ;  teeth  none ;  hosses  near  the  anterior  ex- 
tremity.   Tropical  America  only? 

L.?  elongata  Sw.  Zool.  111.  i.  176.      siliquosa.  Braz.  Test, 
ensiforme  Spix.  Braz.  Test.  pygmea.      IF). 

SympJiynota^  Lea.  A  single  or  double  lamellar  tooth 
extending  the  whole  length  of  the  hinge  margin  ; 
valves  generally  winged  and  connate,  {fig.  123.  ?.) 

plicata  Leac/i.  Zool.  Miss  f  ?  tenuissima.     Am.    Tr.    iii. 

lavissima  Lea.    Am.Tr.  iii.  pi.  11.   f.  21.j: 

pi.  13.  f.  23.  rubens.  En.  Meth.  201.  f.  1. 
bialataZert.  lb.  pi.  14.f.  24. 

Anodon  Lam.     Doubly  winged ;  no  lamellar  or  other 

teeth. 

A.  cataracta      Lam.     vi.     1.      cygnea  Lam.     Gualt.    pi.  7. 
p.  85.  '  f.  F. 

Hemiodon  Sw.      Shell  ovate ;    tubercles  or  undulations 

on  the  hinge  margin^  representing  cardinal  teeth. 

H.  undulatus.  {An.   rugosus     purpurascens  Zool.  111.  i.  160. 
Zool.  111.  i.  96.)  areolata.    Id.  ii.  18. 

Patulavia  Sw.     Shell  nearly  equilateral,  round  or  cor- 
date ;  no  teeth. 
T.  ovata  Sw.    Ex.  Conch,  pi.  36.      rotundatus,  lb.  pi.  137. 

SuB-rA3i.  5.     ALASMODONTIN^. 

Lateral  teeth  entirely  wanting ;  cardinal  teeth  one  or 
two. 

*  Dipsus  Leach. 

f  Differs  from  bialata  by  having  oblique  depressions  towards  the  bosses 
or  beaks,  which  latter  also  are  not  marked  with  "concentric  undulations." 

X  Seems  to  form  the  passage  to  Anodon.  Specimens  labelled  by  Mr.  Lea, 
were  totally  different  from  my  Hem.  purpurascens.  ^ 


382 


SHELLS    AXD    SHELL -FISH.  PART  IT. 


Calceola  Sw.*  Shell  ovate  ;  posterior  hinge  margin 
angulated ;  one  cardinal  tooth,  and  generally  a  small 
single  lateral  tooth  in  each  valve. 

C.  angulata  Sio.    Am.  Tr.   1827,  pi.  3.  f.  1. 

Alasmodon  Say.     Trigonal ;  nearly  equilateral ;  bosses 
large,  prominent ;  two  cardinal  teeth. 
A.  undulata  Say. 

Uniopsifi  Sw.     Oval ;  bosses  prominent ;   cardinal  teeth 
two,  irregular,  receding  from  the  anterior  margin. 
U.  Mytiloides.    (Jig.  62.  )f 

Margaritana  Schum.     Elongated,    and   somewhat    ar- 
cuated ',    bosses   small  ;    posterior   hinge  plate    long, 
convex,  sometimes  with  the  rudiments  of  a   tooth  ; 
cardinal  teeth  two  or  one,  small,  obtuse. 
M.  elongata  Lam.\  arcuata  Barnes. 

Complanaria  Sw.     Shell  winged ;  the  valves   connate  ; 

the  bosses  very  small  and  depressed  ;  cardinal  teeth 

two  or  three  ;  lateral  teeth  represented  by  irregular 

grooves. 

gigas  Sw.  Sow.  Gen.  f.  141.  rugosa  Sw.  {Al.  rugosa)  Barnes. 

Family  2.     ARCADE.     Arch-Shells, 

Marine;  hinge  margin  furnished  with  numerous  small 
well-defined  teeth,  without  any  distinction  of  cardinal 
and  lateral ;  umbones  generally  remote,  mostly  covered 
with  an  epidermis. 

NucuLA  Lam.     Perlaceous  ;  shape  various  ;  beneath  the 
umbones,  a  spatulate  enlargement  or  pit   containing 
the  cartilage  ;   teeth  small,  numerous,  prominent,  and 
pectinate  :  marine  and  fluviatile.     (fg.  125.  f,  g.) 
margaritacea.     Sow.   Gen.  f.  7. 

*  The  situation  of  tliis  type  seems  doubtful,  but  as  I  have  more  than  one 
species  of  the  same  form,  but  without  the  small  lateral  tooth,  I  conjecture 
they  all  stand  between  Alasmodon  and  Anodo?i. 

t  See  note  at  p.  28a 

X  This  is  the  true  ^fl/a  marf^aritifcra  of  British'authors,  for  which  La- 
marck only  quotes  the  fiffures  of  Pennant  and  Da  Costa;  and  as  he  was  the 
first  to  distinguish  it  as  dittercnt  from  the  other  European  species,  I  think 
his  specific  name  has  every  right  of  priority. 


PART  II. 


ATRACBIA.  -   AVICULIDiE. 


383 


Pectunculus    Lam.     Orbicular  :     the  bosses  central ; 
hinge   margin   curved,  with   a  line  of  small  oblique 
teeth  diverging  on  each  side,     {^fig-  125.  a.) 
P.  pilosus.  Sow.  Man.  f.  134. 

Arc  A.  Shell  of  various  shapes,  either  equivalve  or  in- 
equivalve,  but  the  valves  closing  all  round  ;  the  bosses 
very  prominent ;  hinge  margin  always  straight ;  the 
teeth  small.*    {fig.  19,5. b,d.) 

A.  antiquata.    Sow.  Man.  f.  131. 

Byssoarca  f  Stv.     Shell  always  transversely  oblong  or 
oval,   generally    angulated ;    hinge   margin    straight, 
often  auriculated  ;  the  teeth  minute  ;  valves  gaping 
on  the  basal  margin,     {fig.  125.  c,  e.) 
B.  Zebra.   Zool.  111.  ii.  pi.  113.     No®.    Sow.  Gen.  f.  132. 

Trigonia  Lam.  Shell  perlaceous,  sub-cardiform,  one 
extremity  rounded,  the  other  truncated  and  com- 
pressed ;  cardinal  teeth  -,  sagittate,  compressed,  and 
regularly  grooved :  intermediate  between  Byssoarca 
and  Nucula,  and  representing  Cardiiim,  Pandora, 
and  all  the  other  cardiform  types. 

T.  pectinata.    Sow.  Gen.  Man.  f.  139. 


*  The  sub-genera  require  to  be  made  out :  one  of  these  is  Cucullaia. 
t  The  above  remark  is  also  applicable  to  this  group. 


584 


SHELLS    AND    SHELL -FISH. 


PART  II. 


Family  3.  AVICULIDiE.  Muscles  and  Pearl  Oysters. 

Animal  attached,  byssiferous  ;   shells  lamellar,  internally 
perlaceous;  the  valves  generally  gaping,    {fig.  126.) 

Mytilus  Linn.  Oblong,  transverse ;  the  bosses  small, 
close  to  the  anterior  margin ;  both  extremities  rounded ; 
hinge  margin  straight,  and  generally  forming  an  angle ; 
valves  not  always  gaping ;  teeth  (except  in  Bi-achi- 
dontes)  none. 

Brachidontes  Sw.     Umbones  prominent,  not  terminal ; 
valves  corrugated ;  hinge  margin  considerably  angu 
lated ;   teeth  many,  small,  and  crenate. 
sulcata.      En.  Meth.  220.  f.  2. 


Modinla  Lam.  Resembling  the  last,  but  the  hinge 
without  teeth,  and  the  shell  smooth ;  valves  slightly 
gaping,    {fig.  126.  h.) 

M.  tulipa.   Sow.  Gen.  f.  160. 

Lithodomus  Cuv.  Animal  perforating ;  shell  oblong, 
ventricose,  nearly  cylindrical ;  the  hinge  margin  not 


PART  II.  ATRACHIA. AVICULID^.  385 

elevated  ;  umbones  terminal ;  the  posterior  end  some- 
times rostrated.     (Jig,  126,  «.) 

L.  dactylus.    Sow.  Man.  f.  161. 

Mytilus  Linn.  Shell  transverse,  somewhat  triangular, 
from  the  straightness  and  elevation  of  the  hinge  mar- 
gin ;  umbones  minute,  terminal,  sometimes  with  an 
obsolete  tooth. 

M.  achatinus.    Sow.  Man.  f.  158. 

Lanistes  Humph.  Shell  oval,  transversely  cardiform, 
ventricose ;  umbones  prominent,  with  diverging  ele- 
vated striae  ;  hinge  margin  not  elevated  or  angulated; 
teeth  none :   the  cardiform  type. 

discors.      En.  Meth.  ^04.  f.  5. 

Pern  A.  Shells  sometimes  irregular,  inequi  valve, 
oyster-shaped,  greatly  compressed ;  the  margins 
brittle ;  hinge  plate  broad,  with  numerous  teeth,  se- 
parated by  parallel  grooves  containing  the  ligament, 
and  gaping  near  the  umbones. 

Gervillia  Def.  General  form  of  Modiola;  hinge  long, 
straight,  with  small,  irregular,  transverse  grooves. 
Fossil  only. 

G.  avicularis.    Sow.  Man.  f.  169. 

Crenatula  Lam,      Irregularly  oval,   compressed;  hinge 
margin  straight,  with  a  few  semicircular  excavations, 
containing  theligament;  umbones  terminal..(^^.126.«.) 
C.  Mytiloides.    Sow.  Man.  f.  168. 

Perna  Lam.  Shape  various;  valves  always  equally  flat- 
tened; but  the  hinge  margin  always  straight,  not  pro- 
longed; the  plate  marked  with  numerous  transverse 
regular  grooves. 

P.  Ephippium.    Sow.  Gen.  f.  166. 

Pulvinites  Def.  Valves  unequal,  —  one  being  flat,  the 
other  convex ;  hinge  short,  grooved,  as  in  the  last : 
representing  Corhula,  &c. 

P.  Adansoni,    Sow.  Man.  f.  170. 
c  c 


386 


SHELLS    AND    SHELL-FISH. 


PART  II. 


Inoceramus  Sow.  Cardiform^  thick ;  umbones  lateral, 
rather  prominent,  and  incurved ;  hinge  short,  formed 
of  a  series  of  short  transverse  grooves  :   the  cardifornm 

type. 

I.  Lamarck ii.    Sow.  Man.  f.  167. 

Malleus.  Shell  very  irregular,  more  or  less  hammer- 
shaped  ;  the  hinge  margin  being  straight,  and  often 
greater  prolonged ;  the  valves  gaping  to  near  the 
umbones. 

Malleus  Lam.  Hinge  margin  excessively  long,  and 
forming  two  auricles ;  umbones  minute,  depressed, 
with  a  small  disk  for  the  liga- 
ment, and  an  external  groove  for 
the  cartilage. 

M.  vulgaris.  Sow,  Man.  167. 


Reniella  Sw.  Shell  transversely  ^ 
and  irregularly  orbicular ;  sub-  "^ 
ventricose  near  the  umbones, 
which  are  very  small,  termi- 
nal, and  remote;  between  them 
is  a  deep  triangular  concave  pit, 
lined  by  the  ligament ;  the  mar- 
gin of  this  pit  forms  a  semicircle, 
to  the  edge  of  which  is  attached 
a  narrow  cartilage. 

R.  dilatata  Sw.  {fig.  127.) 

Vulsella  Lam.  Shell  tongue- 
shaped,  longitudinally  elon- 
gated, compressed,  without 
auricles  ;  umbones  minute, 
curved,  approximating  ; 
hinge  plate  thick,  diluted 
into  a  semicircular  solid  pit 
for  the  cartilage. 

V.  lingulata.    Sow.  Man.' f.  185.  (fig.128.) 

Avicula.     Shell  regular,  foliaceous,  unequally  auricu- 
lated ;    hinge    margin    straight,    much    lengthened  ; 


PART  II. 


ATRACHIA- 


•OSTRAClDiE. 


387 


umbones  lateral  or  sublateral ;  byssus  protruded  near 
the  umbones. 
Margarita  Leach.  (I8I7.)  Shell  more  or  less  rounded; 
auricles  small ;  umbones  sub-lateral ;  the  hinge  mar- 
gin straight,  but  not  lengthened  ;  teeth  small,  tuber- 
culated,  nearly  obsolete,  {fig.  126.  e.) 
crocata.   Zool.  111.  ii.  pi.  55. 

Aviciila  Lam.     Shell  obliquely  oval ;   the  hinge  margin 
very  much  lengthened,  and  forming  unequal  auricles ; 
teeth  tuberculous,  nearly  or  quite  obsolete,  {^fig. 1'2,1. 
h,  c,  c?.) 
A.  heteroptera.    Sow.  Gen.  f.  1.      aculeata.  lb.  f.  2. 

PiiNNA.     Shell  equivalve,  wedge-shaped  or  triangular ; 
umbones  terminal ;  the  other  extremity  widely  gaping  ; 
hinge  margin  straight ;   teeth  none  ;  anterior  margin 
slightly  gaping.*  {fig.  19.6.  f,  g.) 
P.  serrata.    Sow.  Gen. 

Family  4.    OSTRACTD^.     Oysters. 

Animal  sedentary,  generally  affixed  by  their  under  valve  ; 
shell  foliaceous,  rarely  pearly,   {fig.  129.) 

Peoten  Linn.  Shell  regular,  depressed,  nearly  orbicular, 
auriculated ;  umbones  central ;  ligament  small ;  in- 
ternal hinge  margin  short ;  teeth  straight. 


*  This  genus,  by  coining  close  to  Mytilus  corapletes  the  circle  of  thi» 
family. 

c  c  2 


^ 


388  SHELLS    AND    SHELL-FISH.  PART  II. 

Lima  Linn.  Longitudinally  oval ;  valves  gaping  on 
one  side  near  the  umbones;  animal  similar  to  avicula, 
connecting  this  family  with  the  last. 

L.  squamosa.     Sow.  Man.  174. 

Pecten  Brug.  Shell  generally  free_,  sometimes  slightly 
attached  by  a  byssus  ;  orbicular  or  ovate  ;  auricles 
nearly  equal ;  umbones  central ;  valves  closing  all 
round  ;  hinge  margin  straight ;  no  teeth ;  ligament 
triangular,  internal. 

Decadopecten  Riippell.     General  form  of  Pecten,   but 
with  plicated  teeth  of  the  hinge  :  analogous  to  Nucula. 
D.  plicata     Sow.  Man.  f.  172. 

Pleuronectia  Sw.  General  form  of  Pecten,  but  the 
valves  very  much  compressed  and  gaping  at  their 
edges. 

P.  Icevigata  Sw.    En.  Meth.  208.  f.  3. 

Hinnites  Def.  Animal  attached ;  shell  pectiniform,  but 
irregular. 

H.  pusio.    Sow.  Man.  f.  173. 

Spondylus.  Shell  inequivalve,  attached  by  its  under 
valve ;  rough,  with  spines  and  plates ;  umbones 
central,  remote,  separated  by  a  triangular  disk. 

Plagiostoma  Sow.  Shell  free,  inequilateral,  oblique ;  um- 
bones remote  ;  sub-auriculated   on   one   side  ;  hinge 
straight   in   one  valve,  with  a  triangular  notch  in  the 
other  ;  surface  spinous  or  smooth.      Fossil  only. 
P.  spinosum.      Sow.  Man.  f.  176. 

Spondylus  Lam.  Shell  attached  ;  spinous  and  foliaceous 
externally;  auriculated  hinge^  with  two  teeth  locking 
into  cavities  (Jig.  129.  a.) 

S.  Americanus.      Sow.  Man.  f.  177. 

Dianchora  Sow.     Shell  attached,  obliquely  pectiniform, 
the   attached  valve  having  an   opening  at   the  boss, 
the   other   auriculated  with    an    obtuse    boss ;    teeth 
none  :  passing  into  Ostrea  by  Pedum. 
D.  striata.      Sow,  Man.  f.  175. 


PART  II.  ATBACHIA. OSTRACID^.  389 

OsTREA  Linn.  Shell  foliaceous^  irregular,  generally 
attached  by  the  under  valve ;  hinge  usually  without 
teeth. 

Pedum  Brug.  Shell  hatchet-shaped,  depressed ;  in- 
equivalve,  slightly  auriculate ;  umbones  small,  re- 
mote ;  sides  of  the  lower  valve  turned  upwards,  with 
a  deep  sinus  for  the  passage  of  the  substance  by 
which  it  adheres ;  a  small,  central,  spatulate  tooth  in 
each  valve  bears  the  cartilage,  and  a  transverse  cen- 
tral furrow  between  the  umbones  holds  the  ligament, 
which  spreads  also  between  the  umbones. 

P.  spondyloideuin.      Sow.  Gen.  f.  1 — 5. 

Dendrostran  Sw.     Shell   irregular,  equivalve,  attached 

by  its    lower   valve    by   extraneous    processes ;    the 

margins  solid  and  plicated. 

D.  folium.      Sow.  Gen.   f.  3.     crista-galli.      Sow.  Gen.  f.  2. 
carinata,      lb.  f.  1 . 

Ostrcea  Linn.  Shell  irregular,  round  or  oval,  inequi- 
valve  ;  the  margins  thin  and  brittle  ;  no  teeth ;  um- 
bones central. 

O.  edulis.      Sow.  Gen.  f.  2,       cingulata.      lb.  f.  1. 
Virginica.      lb.  f.  1. 

Gryph(jea  Lam,  Shell  regular, 
inequivalve  ;  one  valve  con- 
vex, with  the  umbo  recurved, 
the  other  smaller,  and  nearly 
flat;  margin  of  the  valves  not 
foliaceous. 
G.  incurva  {fig.l'HO.)    Sow.  Gen.  f.  2.      dilatata.    lb.  f  3. 

PUcatula  Lam.  Shell  irregularly  ovate,  plicated,  in- 
equivalve ;  one  valve  more  convex  than  the  other  ; 
cardinal  teeth  ^  sagittate  ;  the  sides  strongly,  regu- 
larly, and  transversely  grooved ;  between  the  teeth  is 
the  internal  ligament,  (^fig.  I29.  e.) 

P.  gibbosa.      Sow.  Gen.  f.  1,  2. 

Anomia  Linn.  Shell  thin,  perlaceous,  very  irregular, 
inequivalve  ;    attached  by  a  calcareous  mass,  which 


c  c  3 


SQO  SHELLS  AND  SHELL-FISH.  PART  II. 

passes  through  an  opening  near  the  umbo  of  the 
lower  or  smaller  valve,  which  is  flat;  the  other  is 
convex.  (fig.Ug.f.) 

A.  Ephippium.     Sow.  Man.  f.  186. 

Placuna  Brug.  Shell  very  much  compressed^  per- 
laceous^  with  two  internal  lamellar,  sagittate,  cardinal 
teeth  in  one  valve,   {fig.  129-  h,  c.) 

Placunomia.*  Shell  attached,  with  the  form  and  gene- 
ral structure  of  Anomia,  but  with  two  sagittate  car- 
dinal teeth. 

Cumingii.     Sow.  Man.   f.  189. 

Placuna  Brug.  Shell  not  attached,  foliaceous,  roundish  ; 
the  valves  equally  flattened :  united  to  Pecten  by 
Pleuronecta. 

P.  placenta.      En.  M^th.  173.  f.  2. 

Family  5.  ETHERID.iE.     River  Oysters. 

Irregular,  inequivalve,  foliaceous  ;  pearly  within  ;  epi- 
dermis olive  green  ;  ligament  partly  internal  and  partly 
external. 

Etheria  Lam.  Muscular  impressions  two ;  shell  irre- 
gular ;  teeth  none. 

E.  semilunata.      Sow.  Man.  f.  155. 

MuLLERiA  De  Per.     Muscular  impression  single  ;  shell 
sub-quadrate  ;    hinge  irregular  ;   teeth  none. 
M.  lobata.      Sow.  Man.  f.  192. 

Abridged  from  Placunanomia  Sow. 


391 


EXPLANATION  OF  TERMS 

USED  IN  DESCRIBING  THE  SHELLS  OP  TESTACEOUS 

MOLLUSCA. 


Accessary  Valves.  Small  additional  valves  placed  near 
the  umbones  or  bosses  of  the  genus  Pholas  among 
shells,  and  on  the  edges  of  the  pedunculated  bar- 
nacles, among  annulose  animals. 

Acephalous.  Mollusca  without  an  apparent  head, 
comprehending  the  bivalves  of  conchologists. 

Acuminated.  Ending  in  a  graduated  and  often  acute 
point. 

Adductor  muscle.     That  which  closes  the  two  pieces  of 
a  bivalve   together,  the  base  or  insertion  of  which  is 
indicated  by  an  irregular  depression   in   each  valve, 
these  being  called  the  muscular  impressions. 

Anterior,  when  applied  to  the  sizes  of  bivalve  shells, 
is  that  in  which  the  ligament  is  not  placed. 

Apex,  The  point  or  nucleus  of  a  shell ;  hence  the 
bosses  of  bivalves,  the  points  or  top  of  limpets,  or 
of  univalve  shells,  are  so  called. 

Aperture,  or  mouth  of  univalve  shells,  is  the  cavity 
from  which  the  head  of  the  animal  is  protruded. 

Arcuated.     Curved  or  arched. 

Auriculated,  or  eared.  A  term  given  to  a  few  bivalves 
which  have  a  flat  angulated  projection  on  one  or 
both  sides  of  the  umbones,  or  bosses  :  these  processes 
are  most  developed  in  the  Pectens,  and  are  merely 

c  c  4 


392  SHELLS    AND    SHELL-FISH. 

an  incipient  modification  of  the  angular  dilation  of 
the  hinge  margin  in  Byssoarca,  and  several  other 
genera. 

Auriform,  or  ear-shaped^  as  in  Haliotis. 

Base.  This  term  in  regard  to  shells  is  variously  applied  : 
generally  speakings  it  is  used  in  opposition  to  the 
apex  or  end  of  univalve  shells,  although,  correctly 
speaking,  it  is  at  this  part  where  the  head  of  the 
animal  protrudes.  In  such  hivalves  as  adhere  to 
other  substances  by  one  of  their  valves,  as  in  Spon- 
dylus,  Anomia,  Sec.  that  valve  is  termed  the  basal. 
In  unattached  bivalves  the  terra  cannot  be  properly 
employed.  In  reference  to  the  whorls  of  spiral 
shells,  the  last  or  largest  is  termed  the  basal  w^horl. 

Bivalve.   Shells  of  the  order  Dithyra,  having  tAvo  valves. 
Bifid.     Cleft,  or  double. 

Byssus.  A  bunch  of  silk-like  fibres,  by  which  many 
bivalves  adhere  to  other  substances,  without  the  shell 
itself  being  deprived  of  motion.  The  PinncE,  or 
wing-shells,  are  the  most  typical  examples  ;  but 
many  other  genera,  as  the  Pearl  and  Hammer  oysters 
and  even  some  of  the  muscles  are  thus  provided. 
When  dried,  the  byssus  of  the  large  Neapolitan 
Pinna  is  sometimes  fabricated  into  gloves,  but  only 
as  objects  of  curiosity,  since,  as  w^e  know  by  per- 
sonal inquiry,  it  is  a  most  tedious  and  difficult 
process. 

Callous.  When  there  is  a  thickening  of  enamel  upon 
any  particular  part  of  a  shell,  resembling  a  tumour,  it 
is  termed  callous,  or  a  callosity  :  this  is  observed 
among  spiral  shells,  in  the  inner  lip  of  the  Olives, 
Natica?,  and  many  others,  and  is  very  common  near 
the  hinge  of  certain  bivalves. 

Canal.  A  groove  or  gutter  observable  in  different 
parts  of  certain  spiral  shells,  belonging  to  the  Zoo- 
phaga,  or  carnivorous  tribe.  In  these  the  canal  is 
either  lengthened,  as  in  Murex,  short  as  in  Ha)-pa, 


EXPLANATION    OF    TERMS,  393 

or  truncate  as  in  Buccinum  ;  in  the  two  latter  it 
thus  gives  place  to  a  notch,  but  in  all  these  instances 
it  is  that  part  fitted  for  the  protrusion  of  the  long 
cylindrical  siphon  possessed  by  all  these  animals. 
This  part,  also,  constitutes  the  base  of  the  shell.  Be- 
sides this,  there  is  in  many  of  the  mitres,  Stromhi, 
and  other  predaceous  genera,  another  channel  or 
groove,  placed  in  the  interior  of  the  upper  part  of  the 
aperture,  the  use  of  which  has  not  been  fully  ascer- 
tained. 
Cancellated,  When  the  surface  is  marked  by  striae  or 
lines,  which  cross  each  other  at  right  angles. 

Cardinal  teeth  of  bivalves,  are  those  placed  immediately 
beneath  tbe  bosses,  and  between  the  lateral  teeth 
where  such  exist,  as  in  the  common  cockle. 

Carinated,  or  keeled.  Furnished  with  an  elevated,  and 
often  a  sharp  ridge,  either  on  the  surface  or  margin 
of  the  shell. 

Chambered.  Divided  internally  into  compartments,  as 
in  the  testaceous  Cephalopoda,  or  Nautilus. 

Clavate,  club-shaped.  One  extremity  being  slender  and 
pointed,  the  other  thick  and  obtuse.  Many  of  the 
zoophagous  genera,  as  Cerithium,  &c.  are  peculiarly 
strong  examples. 

Columella,  or  Pillar.  The  internal  support  of  most 
spiral  shells,  round  which  the  whorls  convolute :  it 
is  not  present  in  Solarium,  Delphinula,  the  typical 
Scalar ia,  and  a  few  other  genera  ;  all  of  which,  in 
consequence,  have  the  umbilicus  so  deep,  that  it  ex- 
tends to  the  apex  or  top  of  the  shell.  The  basal 
portion  of  the  columella  generally  forms  the  support 
of  the  inner  lip,  and  always  that  around  which  the 
plaits  are  disposed,  as  in  the  Volutes  ;  it  is  some- 
times greatly  thickened,  as  in  Ancillaria,  and  all  the 
Olives. 

Concentric.  Stripes,  grooves,  or  other  external  marks 
indicating  the  progressive  enlargement  or  growth  of 
the  shell :  hence  those  indented  stripes   or   striae   in 


394*  SHELLS    AND    SHELL-FISH. 

bivalves^  which  run  parallel  to  the  margin,  are  termed 
concentric.  Among  spiral  shells  these  indications  are 
less  common,  but  the  Wentletrap  is  a  good  example. 

Corneous.  Resembling  the  colour  or  substance  of  horn  : 
the  epidermis  of  some,  and  the  operculum  of  other 
spiral  shells,  often  present  this  appearance. 

Coronated,  or  crowned.  Spiral  shells  which  have  their 
whorls  more  or  less  surmounted  by  a  row  of  spines, 
or  tubercles,  are  termed  coronated.  The  typical  Vo- 
lutes, or  melon  shells,  several  cones,  mitres,  &c.  are 
thus  ornamented. 

Crenated.  Small  indentations,  generally  sharp  and  re- 
gular, often  placed  on  the  outer  lip  of  spiral  shells, 
particularly  on  many  of  the  typical  mitres,  as  M.  pa- 
palis,  episcopalis,  &c.  Harpa  crenata  is  also  a  good 
example  :  in  bivalves  fewer  examples  occur,  and  these 
only  in  the  teeth,  as  Byssoarca  and  Iridina. 

Cuniform.  Wedge-shaped,  as  Donax :  this  shape, 
comng  bivalves,  is  analogous  to  that  of  clavate  uni- 
valves. 

Deciduous.  Any  part  which  falls  off  in  a  more  ad- 
vanced stage  of  growth,  as  the  terminal  whorls  of  the 
pupaform  land-shells,  to  which,  indeed,  this  pecu- 
liarity is  almost  confined. 

Dextral.  When  the  mouth  or  aperture  of  a  spiral 
shell  is  on  the  right  hand  ;  when  on  the  left,  it  is 
sinistral  or  reversed.  The  great  majority  of  spiral 
shells  are  dextral,  but  frequently  in  the  very  same 
species  (as  in  Bulimus),  individuals  occur  whose  aper- 
ture is  reversed.  This,  by  the  way,  shows  the  in- 
sufficiency of  making  such  deviations  the  ground  of 
generic  distinctions.  In  some  genera,  on  the  other 
hand,  as  Physa,  all  the  species  are  reversed. 

Digitated.  The  expansion  of  any  particular  part,  as  in 
the  outer  lip  of  the  scorpion  Stromhi,  into  finger- 
shaped  processes. 

Discoid,  or  discoidal.  Circular  or  disk-shaped,  and 
much  flattened.     The  freshwater  genus  Planorbis,  and 


EXPLANATION    OF    TERMS.  395 

i 

many  of  the  Helicidce,  or  land-shells,  are  of  this 
form. 
Dorsal.  All  shells  are  dorsal^  because  they  are  all 
placed  upon  the  back  of  the  animal :  the  term^  there- 
fore^ is  only  applicable  to  the  valves  of  bivalves,  and 
merely  serves  to  distinguish  that  part  of  their  cir- 
cumference on  which  the  bosses  are  placed,  in  oppo- 
sition to  that  which,  when  the  animal  is  crawl- 
ing, is  nearest  the  belly.  The  upper  part  of  a  spiral 
shell,  when  the  mouth  is  downward,  may  be  termed 
its  back,  or  dorsal  surface. 

Emarginate.  A  small  notch,  or  fissure,  wherever  it  may 
occur  :  thus  the  base  of  most  predacous  Testacea,  not 
provided  with  a  canal,  are  emarginate ;  so  also  is  one 
extremity  of  Parmophorus ,  although  in  a  very  slight 
degree,  while,  in  the  genus  Emarginnla,  the  notch 
becomes  a  deep  slit. 

Epidermis.  A  name  generally  applied  to  the  outer 
rough  coating  of  shells,  over  which  it  spreads  as  a 
fibrous  horny  skin,  although  not  really  such,  being 
destitute  of  sensation. 

Entire.  Immarginate,  or  uninterrupted,  in  opposition  to 
emarginate. 

Equilateral.     When  both  sides  of  a  bivalve  are  equals 
the  umbones  or  bosses  being  nearly,  or  quite,  in  the 
middle :    this   is   nearly  the   case  with  the   common 
cockle. 

Equivalve.  The  two  valves  of  equal  size  and  depth,  as 
in  the  generality  of  bivalves. 

Fibrous.  Resembling  fibres ;  applied  to  the  substance 
of  a  shell  it  indicates  those,  like  the  Pinna,  whose 
fracture  presents  perpendicular  fibres. 

Fimbriated.  Thin  elevated  processes,  somewhat  re- 
sembling fins,  possessed  by  many  of  the  Murices,  as 
Murejc  fimbriata,  &c.,  and  sometimes  placed  round 
the  aperture  of  cyclostomous  land  shells. 


S96 


SHELLS    AND    SHELL-FISH. 


Foliated.  Resembling  leaves.  As  used  for  the  external 
surface  of  shells,  the  varices,  or  spines,  on  many  of 
the  Murices  are  foliated,  or  divided  at  their  margins 
into  leaf-like  segments,  as  in  the  rosebush  Murex ; 
but  applied  to  the  substance,  it  indicates  those  bivalves 
which  are  composed  of  thin  flat  plates,  very  fragile, 
and  lying  upon  each  other,  as  in  the  common  and 
pearl  oysters.  Sometimes  the  spines  of  bivalves  are 
partly  foliated,  as  in  the  genus  Spondylus. 

Front.  The  front  of  a  shell  is  obviously  that  near 
to  which  the  head  of  the  animal  protrudes :  but  this 
term,  however  objectionable,  is  given  to  the  under 
surface  of  spiral  shells,  or  that  where  the  aperture  is 
placed,  in  contra-distinction  to  the  back. 

Fusiform,  or  spindle-shaped  ;  thickest  in  the  middle, 
and  attenuated  or  tapering  to  the  extremities.  Fusus, 
Fasciolaria,  and  many  mitres,  are  more  or  less  of  this 
form. 

Gaping,  A  bivalve  is  called  gaping,  when  any  part  of 
the  margins  do  not  touch. 

Gibbous,  or  humped.  Any  part  of  a  shell  more  par- 
ticularly elevated  above  the  surface,  or  unusually  so  in 
comparison  to  other  species,  is  termed  gibbous,  as 
Strombus  gibbosus. 

Granulated,  or  grained.  Marked  by  elevated,  close  set, 
and  regular  dots,  resembling  grains :  this  appearance 
is  very  common  at  the  base  of  the  predaceous  spiral 
genera. 

Hinge  margin  in  bivalves,  see  Dorsal  margin.  The 
hinge  is  composed  of  the  ligament,  the  cartilage,  and 
the  teeth. 

Hyaline.  Of  a  glassy,  thin,  and  semi-transparent  sub- 
stance. 

Imbricated.  Plates  or  folds  laid  over  each  other,  like 
tiles  on  the  roof  of  a  house. 


EXPLANATION    OF    TERMS.  397 

Incrassated.  Any  part  more  thickened  than  usual,  or 
than  the  surrounding  surface.  The  inner  lip  of 
Oliva  and  the  hinge  of  Glijcimeris  are  good  examples 
among  the  spiral  and  acephalous  tribes. 

Incurved.     The  point  turned  inwards. 

Indented.  A  term  of  very  comprehensive  meaning  :  it 
is  used,  generally,  to  express  any  thing  depressed  or 
sunk  beneath  the  surrounding  surface,  whether  they 
are  lines,  dots,  irregular  cavities,  or  tooth-like  depres- 
sions. Many  shells  are  marked  by  indented  strise. 
The  suture  of  others  is  also  indented. 

Inequivalve.  One  valve  smaller  than  the  other,  as  in 
Anomia  and  Terebratula, 

Inferior  valve  of  adherent  bivalves,  is  that  by  which  the 
shell  is  united  to  other  substances. 

InHated.     See  Ventricose. 

Irregular  bivalves.  Such  as,  from  being  influenced 
in  their  growth  by  the  substances  in  which  they  re- 
side, do  not  present  a  uniformity  of  shape  in  the  in- 
dividuals of  the  same  species.  This  variation  is 
almost  confined  to  the  perforating  groups ;  among 
which,  however,  as  in  Lithodomus,  this  deviation 
from  a  uniform  specific  shape  is  not  found. 

Lamellated.  Shells  whose  substance  is  composed  of 
very  thin  plates  or  lamellae,  which  do  not  present  a 
solid  surface,  as  in  the  pearl  oysters. 

Lateral.  Any  thing  on  the  sides  of  a  shell.  Thus  the 
lateral  teeth  of  bivalves,  where  they  exist,  are  on  one 
or  both  sides  of  the  cardinal  teeth,  which  are  always 
central. 

Length  of  shells.  Spiral  shells  are  measured  from  the 
tip  of  the  spire  to  the  base,  and  therefore  perpen- 
dicularly :  but  the  length  of  bivalves  is  taken  hori- 
zontally ;  thus  the  Soleus  are  the  longest  shells  of 
this  tribe,  the  length  being  taken  from  the  anterior 
to  the  posterior  margin. 


398  SHELLS    AND    SHELL-FISH. 

Ligament,  An  exteranl  substance,  by  which  the  two 
valves  of  acephalous  Testacea  are  united,  and  which, 
in  fact,  is  the  true  hinge.  The  internal  part  is  gene- 
rally composed  of  another  substance,  called  the  car- 
tilage, of  a  compact  fibrous  structure,  which  is  elastic 
when  moistened,  but  very  hard  and  solid  when  dry. 
This  is  generally  placed  close  to  the  bosses,  and  is 
often  continued  between  the  teeth,  so  as  to  form  a 
second  or  internal  ligament. 

Lips.  The  two  sides  of  the  aperture  of  spiral  shells  are 
termed  the  lips.  That  which  joins,  and  generally 
folds  over,  the  lower  part  of  the  columella,  is  called 
the  inner  lip,  while  that  part  of  the  circumference 
opposite  is  the  outer.  The  latter,  of  course,  is  found 
in  all  shells,  because  it  is  the  termination  of  the  last 
whorl  ;  but  the  inner  lip  is  frequently  absent,  or  only 
indicated  by  a  thin,  whitish,  almost  transparent 
enamel':  sometimes,  however,  it  is  highly  developed, 
as  in  Nassa,  the  typical  Cassides,  or  helmet-shells, 
and  several  others. 

Lobed.  A  broad  obtuse  division,  as  in  many  of  the 
Strombi  and  Pleurotomince. 

Longitudinal.  The  meaning  of  this  term,  as  used  and 
understood  by  all  the  best  conchologists,  is  "  length- 
wise ;"  hence  it  means  any  stripes  which  run  in  a 
perpendicular  direction  from  the  apex  to  the  base  of 
spiral  shells,  while  such  as  are  in  a  contrary  direc- 
tion— that  is,  parallel  to  the  suture  of  the  whorls, 
are  transverse.  Great  confusion,  therefore,  is  likely 
to  be  introduced  by  reversing  these  definitions.* 
However  objectionable  they  may  be  thought  by  fas- 
tidious persons,  we  always  have  and  shall  continue 
to  designate  the  direction  of  stripes,  bands,  or  other 
peculiarities,  as  longitudinal  when  they  run  in  the 
direction  of  the  length  of  a  spiral  shell,  and  ti'ansverse 
when  they  cross  its  breadth.  The  latter  term,  how- 
ever, is  not  applicable  to  bivalves,  because  such  marks 

*  As  is  done  in  the  Conchological  Manual. 


EXPLANATION    OF    TER3IS  399 

always  spring  from  the  bosses^  and,  widening  as  they 
approach  the  ventral  margin,  become  radiated. 

Lunate,  or  lunulate,  assuming  the  form  of  a  crescent  o. 
half-moon.  Tiie  aperture  of  the  nerits  is  of  this  de« 
scription,  as  well  as  the  muscular  impressions  of 
most  bivalves. 

Mamillary,  or  mamillated.  Smooth,  thick,  and  obtuse, 
like  a  teat.  The  apex  of  the  typical  volutes,  as 
Voluta  olla,  Diadema  &c.  are  strictly  of  this  de- 
scription, as  also  those  of  Harpula  fulgetrum,  Sea- 
phella  papulosa,  and  other  volutes  :  but  C.  vesperiilio 
is  not  so,  for  the  spire  is  distinctly  plaited^  and  even 
rough  with  obsolete  spines. 

Measurement,  see  Length. 

Multivalve.  The  oiily  multivalve  Testacea,  properly 
so  called,  are  the  chitons  and  the  perforating  genera 
belonging  or  closely  allied  to  Teredo  and  Pholas.  The 
Cirripedes  are  annulose  animals  or  insects_,  and  have 
no  place  whatever  among  the  molluscous  tribes,  any 
more  than  beetles  or  butterflies. 

Muscular  Impressio7is :  those  indented  marks  in  ace- 
phalous bivalves,  indicating  the  insertion  of  those 
muscles  by  which  the  animal  is  attached  to  its  shell. 
Of  these  there  are  three  principal  sorts, — lateral, 
central,  and  paUial.  1 .  The  lateral  impressions  indicate 
the  animal  to  have  two  adductor  muscles,  as  in  Unio 
Cardium,  and  aU  the  most  typical  bivalves.  2.  A 
central  impression  shows  us  the  presence  of  but 
one  adductor  muscle,  which  is  generally  in  the  middle 
of  the  shell,  as  in  the  common  oyster.  AU  these 
shells,  however,  are  furnished  with  the  third  or  pal- 
lial  muscle,  which  is  indicated  by  a  depressed  line, 
often  sinuated,  running  parallel  with  the  ventral 
margin. 

Obsolete.  This  term,  in  conchology,  is  more  properly 
restricted  to  implying  a  faint  indication  of  par- 
ticular characters.     Thus,  very  slight  and  partially 


400  SHELLS    AND    SHELL-FISH. 

indistinct  stria  upon  a  shell  are  called  obsolete  strice, 
not  because  they  are  worn  off'  by  accident,  but  be- 
cause they  are  only  rudimentary,  or  very  slightly 
developed. 

Operculum.  The  hard  lid,  either  corneous  or  cal- 
careous_,  which  closes  the  mouth  of  many  spiral 
shells,  and  is  carried  on  the  posterior  part  of  the 
belly  of  the  animal.  It  generally  fits  the  aperture 
of  the  shell,  but  is  sometimes  smaller,  in  which  case 
it  is  drawn  inside  until  the  animal  adjusts  it  to  the 
diminished  circumference  of  the  whorl.  Nearly  all 
the  predaceous  tribes  have  this  protection  ;  but  it  is 
never  found  among  such  as  envelop  their  shell  in  the 
lobes  of  their  mantle. 

Ovate.  Not  oval,  but  egg-shaped ;  one  extremity  being 
thicker  and  more  obtuse  than  the  other. 

Patelliform.     Dish  shaped,  as  the  limpets. 

Pectinated.  Processes  resembling  in  form  and  arrange- 
ment the  teeth  of  a  comb,  as  are  the  spines  of  some 
species  of  Murex. 

Perforated.  As  if  bored  or  indented  by  an  awl  :  the 
holes  or  perforations  in  the  ear-shells  are  of  this  de- 
scription. 

Plicated.  Applied  to  any  part  of  a  shell  which  has 
plaits  or  folds,  either  upon  the  pillar  or  the  external 
surface:  the  concentric  ridges  so  common  in  the 
genus  Venus  are  also  of  this  description. 

Posterior  margin.  This  term  is  confined  to  acephalous 
bivalves,  and  is  that  side  of  the  bosses  which  contains 
the  ligament. 

Ramose.  Spines  upon  shells  which  send  out  others  in 
a  lateral  direction,  are  termed  ramose  or  branched. 

Recurved.  Turned  backwards,  in  contra-distinction  to 
incurved.  The  canal  of  some  Strombi  and  Cerithiinn 
are  remarkably  recurved.     The  apex  of  all  the  patelli- 


EXPLANATION    OF    TERMS.  401 

form  shells,  however,  are  not  always  incurved,  the  top 
bending  downwards  or  being  erect. 

Reflected.  Turned  or  folded  backwards,  as  is  the  thick- 
ened outer  lip  of  the  common  garden,  and  many  other 
of  the  terrestrial,  snails. 

Reverse  Shells,  are  such  as  have  the  aperture  opening 
on  the  left  side  when  it  is  placed  in  front  of  the  spec- 
tator. 

Sinuated,  or  waved.  Any  part  whose  margin  has  one 
or  more  undulations  :  this  appearance  is  produced  by 
a  projecting  lobe  being  followed  by  a  notch  or  hoUow 
more  or  less  deep.  The  outer  lip  of  Struth'wlaria  and 
several  of  the  Stromhi  are  sinuated,  but  the  latter  so 
much  so  as  to  form  abrupt  lobes  and  corresponding 
notches. 

Sessile.  Destitute  of  any  support  or  peduncle,  as  in  the 
shell  of  the  Anomia.  Those  of  Terebratula,  on  the 
contrary,  are  elevated  in  some  degree,  on  a  pedunclcj 
and  are  termed  pedunculated. 

Siphon.  A  sucker:  a  fleshy  process,  generally  long, 
cylindrical,  and  hollow  ;  protruded  by  the  carnivorous 
and  testaceous  animals  from  the  base  or  channel  of 
their  shells.  The  same  term  is  given  to  the  slender 
shelly  tube  which  connects  the  chambers  of  cephalo- 
pod  shells,  or  the  Nautili. 

Spire.  Those  volutions  of  a  spiral  shell  which  are 
above  the  lowest  or  body- whorl,  collectively  form  the 
spire  of  the  shell,  M'hatever  shape  it  may  assume. 
The  variations  in  the  form  of  this  part  are  num.erous. 
In  some  it  is  excessively  lengthened;  in  others  it  is  not 
even  raised  above  the  body- whorl.  In  Plcmorhis  the 
spire  is  sunk,  while  in  CyprcBa  it  is  so  small  as 
only  to  be  seen  when  the  shell  is  young,  after  which 
it  is  covered  over  by  the  enlargement  of  the  body- 
whorl  or  principal  volution. 

Squamose.     Having  the  appearance  of  scales. 

D  D 


402  SHELLS  AND  SHELL-FISH. 

Striated.  Marked  with  lines,  either  elevated  or  raised,, 
at  parallel  and  nearly  equal  distances.  Such  marks 
are  termed  striae  only  when  they  are  very  slender^ 
not  much  exceeding  the  breadth  of  a  hair,  or  at  most 
of  the  human  nail :  when  they  are  deeper  and  in- 
dented, they  are  termed  grooves ;  or,  if  elevated, 
ridges.  Sometimes  the  striae  are  formed  by  a  series 
of  punctures,  as  in  Mitra  cardinalis,  &c.  ;  while  in 
other  instances  they  are  elevated  and  granulated,  as 
Mitra  granulosa.  In  bivalve  shells  they  are  almost 
always  concentric,  or  following  parallel  to  the  outer 
margin.  All  these  variations  have  been  found  of 
great  importance  in  the  determination  of  species,  and 
hence  require  the  closest  attention. 

Suh.  Nearly  or  partially,  as  sub-striate,  sub-fusi- 
form, &c. 

Subulate.  Awl-shaped,  long,  slender,  and  acutely 
pointed,  as  Terebra,  Tu7'ritella,  &c. 

Sulcated.  Broad  grooves,  sunk  beneath  the  surround- 
ing surface. 

Suture.  A  term  applied  to  the  line  of  junction  in  the 
whorls  of  spiral  shells^  or  that  where  two  parts  join 
or  fit  into  each  other. 

Symmetrical.     Where  the  two  sides  of  a  shell  are  alike. 

Terebrating  Testacea  are  such  as  take  up  their  habi- 
tations in  other  substances,  as  Pholas,  &c. 

Tessellated.  Divided  into  squares  or  chequers,  either 
by  a  division  of  the  colours,  or  by  the  crossing  of  the 
stris. 

Transverse.  A  line  drawn  across  the  breadth  of  a  sliell. 
Thus  the  coronations  of  the  Volutes  are  transverse, 
so  also  are  the  bands  on  the  AcJiatince,  and  all  those 
upon  bivalve  shells  which  radiate  from  the  bosses. 

Trigonal  or  triangular.     Having  three  equal  or  unequal 

sides,  as  Donax,  Hyria,  Cardissa,  &c. 
Trilobate.     Divided  into  three  obtuse  divisions  or  lobes. 


EXPLANATION    OF    TERMS.  403 

Tricuspidate.     When  these  divisions  end  in  points. 

Truncated.  Ending  abruptly^  as  if  cut  off,  as  in  the 
extremities  of  the  typical  Soleus,  Mya  truncata,  8cc. 
The  same  term  may  be  applied  to  the  termination  of 
the  spire  in  several  land-sheUs,  which  seem  as  if 
they  had  been  broken  off. 

Tuhivalves.  Such  bivalves,  like  Teredo,  as  are  pro- 
vided also  with  a  tube. 

Turbinated.     Turban    or  top-shaped  j   the  whorls  con 
vex,  and  generally  but  very  little  raised.    The  garden 
snails  are   good  examples,  but  not  the  TrocM,  thai 
form  being  pyramidical. 

Umbilicus.  A  hollow  opening,  more  or  less  wide, 
on  the  side  of  the  inner  lip  of  spiral  shells :  in  some, 
as  Scalaria  and  Sollarium,  it  is  so  deep  as  to  ex- 
tend to  the  apex  of  the  shell ;  in  others,  as  Tro- 
chus,  it  is  small ;  in  Bulimus  it  becomes  nearly 
obsolete  ;  and  in  N'atica  it  is  often  entirely  con- 
cealed by  the  spreading  of  the  inner  lip.  In  all 
these  variations,  however,  the  umbilicus  is  caused  by 
the  inner  edges  of  the  whorls  not  touching  each  other. 
Instances  occur  in  certain  land-shells  which  are 
deeply  umbilicated  when  young,  but  not  at  all  when 
old. 

Undulated.  Waved  ;  nearly  synonymous  with  sinuated, 
but  more  particularly  applied  to  the  colouring  of 
shells.  Scapella  undulata  and  many  other  volutes 
are  marked  in  this  way. 

Valves.  The  two  ordinary  or  principal  pieces  which 
comprise  the  covering  of  acephalous  Testacea,  or 
bivalves. 

Varix.  Those  strong  elevated  ridges  which  cross 
the  whorls  of  several  of  the  predaceous  genera, 
as  Murex,  Triton,  &c.  :  they  mark  the  progressive 
enlargement  of  the  sheU,  being  the  remnants  of 
former   apertures,   beyond   which  the  animal,  when 

D  u    2 


404<  SHELLS    AND    SHELL-FISH. 

grown,  forms  another  aperture.  Sometimes,  as  in 
Murex,  these  varices  are  irregular,  and  are  either 
spined  or  foliated  ;  but  in  the  harp-shells  they  are 
smooth  and  at  equal  distances.  In  Ranella  they  are 
united,  so  as  to  form  two  lateral  ridges  ;  while  in 
Triton  they  are  detached  and  remote  from  each  other. 
In  Cassis  they  are  also  alternate  ;  and,  in  the  aberrant 
species,  none  whatever  are  perceived. 

Volution.      Synonymous  with  whorl. 

Whorl.  Each  complete  turn  of  the  spire  in  a  spiral  shell 
is  termed  a  whorl :  th€  last,  which  terminates  with  the 
aperture,  is  the  body  or  basal  whorl ;  the  rest  are 
the  spiral  whorls. 


APPENDIX. 

S-u.  r  /f,4r ■" 

The  following  note  on  the  extraordinary  genus  Herpa,  from 
the  Guilding  MSS.,  and  referred  to  in  the  text,  is  too  valu- 
able to  be  omitted. 

HERPA    Guilding. 

Animal  terrestre,  pulmoniferum.  Corpus  moUe,  subgelati- 
aosum,  mucrone  obductum,  elongatum,  contractile,  depressum, 
antice  praesertim  attenuatum.  Os  apicale,  minutissimum, 
obscurum.  Fades  contracta,  emarginata.  Tentacula  nulla. 
Scxttum  nullum.  Oculi  cervicales.  Solea  magnitudine  corporis, 
nee  distincta.  Glandules  plurimae  ventrales  mucorem  ab  ore 
transverse  eflfuadentes,  unica  majore  centrali,  equa  viscus  lo- 
batum,  moUe,  plicatile,  parvulum,  rare  protruditur. 

Genus  valde  distinctum,  et  inusitatae  formae.  Corpore  fere 
toto  erecto  Herpa  more  serpentum  prolabitur,  viam  mucore 
superillinens,  et  tentaculis  carens  cervice  longo  valde  attenuate 
vestigia  diriget.  Genus  Planariis  facie  quam  plurimum  analo- 
gum,  ut  Limacibus  respirationis  modo,  locis,  moribusque 
omnino  affine. 

In  the  8th  number  of  the  Zool.  Journ.  p.  443.  a  short  notice 
of  this  genus  was  given,  drawn  from  a  single  specimen  which 
must  now  be  struck  out.  The  capture  of  many  of  them  has 
enabled  me  materially  to  improve  the  description.  They  are 
very  singular  animals,  and  in  their  external  characters  have  a 
remarkable  resemblance  to  the  Planarice,  which,  however,  as 
Cuvier  observes,  inhabit  only  salt  or  fresh  water,  and  therefore 
can  have  no  relation  of  aflBnity  with  Herpa.  Probably,  the  PL 
ierrestris  and  Candida  of  Gmelin  may  resemble  them  in  their 
economyo     I  have  found  the  Herpes  on  the  decayed  fronds   of 

D   D    3 


406 


APPENDIX. 


palms,  on  the  summits  of  high  mountains,  and  on  the  dry  lands 
within  a  few  yards  of  the  sea ;  these  always  seeking  cool  places 
for  concealment  during  the  day,  but  never  approaching  the  water, 
which  upon  being  thrown  into,  they  instantly  quit."  The 
largest  of  the  three  species  discovered  by  our  author,  was  Her- 
pa  gigas,  black  above,  dirty  and  paler  beneath.  It  was  from 
six  to  seven  inches  long,  and  was  found  creeping  across  a  damp 
forest  path ;  but  from  the  strange  power  it  possesses  of  contrac- 
ting its  body,  it  escaped  through  a  small  crevice  of  the  box  it 
was  deposited  in,  before  it  could  be  more  accurately  examined. 


INDEX. 


***  The  page  references  are  to  the  Author''s  remarks :  to  avoid  a  multipUcUy 
of  figures,  the  reader  is  referred  to  the  occasional  tables  for  the  classifica- 
tion of  genera. 


AcARDO,  373. 

Acephala,  the  naked,  5.  n.  The  bi- 
valve Testacea,  25. 

Achatinse,  snails  with  elongated 
spiral  shells,  1G2.  174.  179.  334. 
Sub-typical,  170.  335,  oSQ.  A. 
marginata,  170.  Sub-genera  and 
analogies,  173.  175.  179.  5oQ. 
Point  of  union  with  the  Bulimi- 
r\dz.  183. 

Achatinellffi,  172.  338. 

Acrita,  their  nervous  system  gra- 
nular, 4.  n.  Probably  consists  of 
polypes,  corals,  and  plant-like 
animals,  5.  The  group  seems  to 
to  be  ill-definedby  naturalists,  43. 

Adanson,  on  the  shell-fish  of  Sene- 
gal, 14. 

Adhesion,  power  of,  often  by  in- 
numerable suckers,  30,  31.  Of 
the  Patella  to  rocks,  244. 

iEglia,  genus,  265. 378.  Represents 
Hyria,  275. 

Affinity,  theory  of,  5.  7.  94.  189. 
291.  Of  Testacea,  form  a  conti- 
nuous circle,  41.  et  passitn. 

Akera,  249. 

Alee,  183. 

Alasmodon,  263,  264.  273.  381. 
A.  undulatus  and  calceolus,  263. 
288,  289.     A .  rugosus,  273. 

Alasmodontinffi,  the,  276.  287.  381. 
Connection  with  Anodons,  288. 
Analogies  of  the  genera,  290. 

Amphibia,  allusions  to,  50. 

Amphidesma,  371. 

Amphiuma,  worm-like  salaman- 
ders. 43. 

Ampullaria,  genus,  55.  339.  Siphon 

•    of,  160. 


Ampullarinse,  or  apple-snails,  1P5. 
339.     Guilding's  drawing  of,  Jbi7. 

Analogies,  in  Malacology,  different 
from  athnities,  42.  183.  291.  Con- 
sist of  mutual  representations,  49. 
Of  Annelides  with  Nudibranchia, 
51.  Of  Parenchymata  with  annu- 
lose  Vermes,  52.  Ofzoophagous 
and  phytophagous  Gaste.opoda, 
111.  See  various  classes  and  ge- 
nera. 

Analogy,  averification  subordinate 
to  that  by  affinity,  94. 

Anastoma,  sub-genus,  192.  329. 

Ancillaria,  aberrant  group,  97,  98. 
132.  323.  Resemblance  to  Con- 
cholepas  and  Monoceros,  100. 

Ancillarinae,  sub-.^amily,  Itil.  133. 
322. 

Anculosa,  fluviatile,  199.  210.  340. 

Ancylus,  freshwater  limpets,  188. 
338. 

Annnal  kingdom,  links  of  compa- 
rison and  resemblance  betwixt 
various  classes  of  the,  5.  7.  40.  42. 

AnimalculcK,  classification  of,  45. 

Aimelides,  ring-jointed,  and  hav- 
ing red  blood,  7.  Resemblances 
of,  to  fishes,  7. ;  and  to  Testacea, 
27.  51.  Analogy  with  Nudibran- 
chia, 51. 

Annulcsa,  the,  or  insect  tribes,  2. 4. 
Circle  or  group  of,  38.  51.  Ana- 
logies of,  52. 

Anodon,  genus,  263.  287.  Small 
depressed  summit  of,  273.  A.  ana- 
tinus,  286.  Various  other  spe- 
cies of,  286,  287. 

Anodontinffi,  the,  259.  286.  381. 
Analogies  of,  287. 

Anomia,  47-  389. 

Aphorrais,  138.  141.  157.  309.      Its 

D  D    4< 


40o 


INDEX. 


resemblance  to  Cerithium,  142.  ; 
to  Rostellaria,il42. ;  to  Pterocera, 
142. 

Aplustra,  360.     A.  pulchella,  24P. 

Aplysia,  sea  hares,  25.  30.  238.  248. 
Typical  characters  of,  250.  359. 

Aplysianae,  sub-family,  359. 

Aptera,  a  sub-typical  class,  51.  55. 

Area,  genus,  383. 

Arcidai,  or  arch-shells,  260.  382. 

Argonauta,  48. 

Aristotle,  the  acknowledged  leader 
of  zoological  science,  13. 

Arrangement,  natural,  295. 

Aspergillium,  the  animal  lives  in 
sand,  362. 

Atrachia,  tribe  of,  255,  256.  377. 
Circle  of,  perfected,  258.  Analo- 
gies of,  258. 

Auricula,  171.  209.  337.  Genuine, 
176.  178.  Sub-genus,  180.  Spe- 
cies of,  180. 

Aves,  circle  of,  perfectly  developed, 
41.  Certain  analogies  with  typi- 
cal Gasteropoda,  &c.,  49. 

Avicula,  description  of,  257.  386. 

Aviculidae,  the,  257.  Muscles  and 
pearl  oysters,  383. 

Azeca,  sub-genus,  183. 


B, 


Balia,  182,  3.34. 

Barnacles,  classification  of,  25.  28. 

Their  analogy  with  cuttlefish,  52. 
Belemnites,  fossil,  48. 
Bibliography    of     the    testaceous 

MoUusca.  notice  of  the,  13,  et  seq. 
Bicatillus,  354. 
Biconia,  355. 
Birostra,  form  of,  325. 
Bivalves,    Aristotle's   designations 

of  the  molluscous,  13.  21.     Ace- 

phala,  25.     Double  shells,  as  the 

oyster    and    cockle,    27.         All 

aquatic,    33.        Sub-typical,    S5. 
'•    Devoid  of  eyes  and  tentacula,  36. 

Some  analogy  of,  with  Aves,  50. 

Order  of  Dithyra,  254.  361.    Flu- 

viatjle,  259. 
Blainville,   M.   de,  system   of,   17, 

His   nomenclature  objectionable, 

13. 17. 
Brachidontes,  383. 
Brachytoma,  new  genus,  154.  314. 
Branchiopoda,  of  Cuvier,    23.    47. 

Anomian  shells,  25.  47.  256. 
Buccininas,  or  whelks,  63.  71.    Base 

abrupt  and  notched,  73.  97.  301. 
Buccinum,    genus,     62.    96.    302, 

B.  Achatinum,  74.  B.  la^vigatum, 

74.    B.  plumbeum,  82.    B.  strom- 

bioides,  123. 
Bulimus,  description  of,  170.  176. 


oflB.    B.  proper,  177.    Sub-genus, 

178.     Analogies  of  its  sectional 

types,  179. 
Bulimi,  conical  spire  of  the,  163. 

177.    Sub-genera  of,  178.    Circle 

of,  181. 
Bulimulus  undulatus,  antiquensis, 

and  proteus,  177.  335. 
Bulla,  conformation  of,  25.  55.  .360. 

Connected   with    the  Cvpraeidae, 

59.  238.      B.   naucum,  249.     B. 

aperta,  252. 
Bullinas,   sub-family  of,   248.  251. 

3.59. 
BuUinula,  of  Beck,  360. 
Bursatella,  structure  of,  251.  359. 


Calceola,  382.     C.  truncata,  289. 

Calliostoma,  sub-genus,  218,  219. 
351. 

Callithea,  conformation  of,  320. 

Calliscapha,  380. 

Calyptrea,  230,  231.  354.  Natural 
station  of,  233.    C.  chinensis,  234. 

Cancellaria,  small  incurved  chan- 
nel  of,  79. 305. 

Cancilla,  described,  320. 

Canthapleura,  357- 

Canthella,  202. 

Canthidomus,  342. 

Canthorbis,  diversified  sub-genera, 
216.  349.  Sub-genera  and  ana- 
logies of,  224 

Canthyria,  276.  378. 

Capsa,  373. 

Capulis,  244. 

Caracolla,  328. 

Cardissa,  257.  259.  373. 

Cardita,  375. 

Cardium,  373. 

Carinea,  326. 

Carinaria,  48. 

Carinidea,  sub-genus,  216.  350. 

Carrier  shells,  212.  217.  228. 

Cassida?,  analogies  of,  89.  100. 

Cassidaria,  of  Lamarck,  69.  71.  299 

Cassidea,  66.  Form,  and  species  of, 
299. 

Ca.ssinaD,  or  helmet-shells,  63.  65. 
297.  Separate  circle  of  affinity, 
66.  95.  Analogies  to  the  Gaste- 
ropoda, 66. 

Cassis,  genus,  65.  68.  71.  Species 
of,  298. 

Castalia,  of  Lamarck,  284.  379.     C. 

-   cordata,  284. 

Cemaria,  of  Leach,  243.  356. 

Cephalopoda,  jirovided  with  a  back- 
bone, form  an  order  connected 
alike  with  the  Vertebrata  and 
Mollusca,  5,  et  srq.  Perfection 
of  sight  of,  8.    Lamarck's  table 


INDEX. 


409 


of,  24,  Cuvier's  classification  of, 
25.  Swimming,  and  fins  of,  31. 
Search  for  its  prey,  34.  High 
organisation  of,  38.  Vestiges  of 
testaceous,  40.  Affinities  of,  48. 
Extinct  or  fossil  genera  of,  48. 
Their  analogy   with   fishes,  51 ; 

■'  and  with  barnacles,  52. 

Ceratodes,  sub-genus,  197.  339. 

Ceriphrasia,  siib-genus,  204.  Ano- 
malous, 205. 342. 

Cerithidea,  198.  203.  342. 

Cerithins,  or  club-shells,  137.  139. 
156.    Characters  of,  315. 

Cerithium,  affinities  of,  47. 136.  142. 
205.     Typical  genus,  157.  315. 

Chama,  how  cemented  or  affixed  to 
rocks,  &c.,32.  47.  374. 

Chamidffi,  the,  257.  374. 

Chelidomus,  analogies  of,  192. 

Chelinotus,  group  of,  234.  S55. 

Chelosomje,  36.  Organisation  of, 
45.  238.  255,  256. 

Chiton,  of  Linnaeus,  357. 

Chitonellus,  246.  358. 

Chitones,  or  Cyclobranchia,  25.  55. 
238.  360.  Their  organisation,  45. 
Boat-shaped  shells  of,  58.  Struc- 
ture of,  246. 

Chlorostoma,  formation  of,  218. 
350. 

Chrysodomus,  characters  of,  90. 308. 

Chrysostoma,  description  of,  353. 

Cidaris,  characters  of  the  genus,  215. 
349. 

Circle  connecting  Testacea,  theory 
of  a,  40.  95.  Circle  of  existing 
birds,  41.  Of  extant  and  of  ex- 
tinct Reptilia,  41.  Of  the  entire 
class  of  Testacea,  traced,  46.  48. 
Of  the  entire  Animal  Kingdom, 
49. 

Cirripeda,  articulated  limbs  of  the, 
6.  First  group  of  Annulosa,  6. 
Barnacles,  25.  28.  Relationship 
between  Cephalopoda  and,  52. 

Clausilia,  genus,  161.  Characters 
of,  182.  334.  Analogies  of,  184. 
209. 

Clavagella,  363. 

Clavalithes,  fossils  of  the  Turbi- 
nell£B,  77.  94.    Characters  of,  304. 

Clavatula,  of  Lamarck,  137.  155. 
314. 

Clavicantha,  155.  314.  C.  echinata 
and  auriculifera,  fluviatile,  155. 

Cleidothasrus,  374. 

Clithon,  347. 

Clypidella,  356. 

Cochlicopa,  171.  173.  335. 

Cockle,  the,  27.  What  called  its 
foot,  30. 

CoDcilia,  44. 

Columbella,  135.  313.  C.  merca- 
toria,  150.    C.  nitida,  151. 


Columbellinje,  61.  134.  Conform- 
ation of  the  dove-shells,  1S7.  150. 
The  typical,  143.  312.  Operculum 
of,  150.  The  genera  of,  152.  Ana- 
logies of,  153. 

Complanaria  gigas,  288,  290.  382. 
C.  rugosa,  288. 

Conchifera,  of  Lamarck,  22. 

Concholepas,  73.  100.  301. 

Conchology,  definition  of,  10.  The 
interests  of  geology  require  that 
shells  should  be  scientifically  stu- 
died, 12.  Advantage  of  a  genuine 
classical  nomenclature,  13.  In- 
feriority of  modern  compound 
names,  13.  The  Linnjean  no- 
menclature, 14.  System  of  Lin- 
neeus,  15,  16.  Plates  by  D'Ar- 
genville  and  others,  14.  Merits 
of  the  chief  modern  writers  on, 
15, 16.  e(  passim.  Great  difficulty 
of  completing  a  general  and  illu- 
minated work  on,  IS.  Theory  of 
a  perfect  circular  group  of  all 
the  Testacea,  40. 46.  Knowledge 
of  the  animals  increased,  97. 
Mr.  Cuming's  discoveries,  127. 
Theory  of  variation,  127.  Sys- 
tematic arrangement  of,  127.  295. 
Glossary,  391. 

Conella,  312. 

Cones,  smooth  shells  of  the,  61. 116. 
311.  With  coronated  tubercles, 
116.  The  Coninae  described, 
137.  310.  Their  genera,  150.  311. 
Their  connection  with  the  Strom- 
bina?,  146.  Analogies  and  cha- 
racters of  the  sub-genera  of,  148. 
150. 

Conidea,  characters  of,  151. 153.  313. 

Conilithes  antediluvianus,  311. 

Concehelix,  remarks  on,  127.  129. 
321. 

Concelix,  characters  of,  321. 

Conorbis  dormiter,  312. 

Conus  amadis,  143.  C.  bandanus, 
147.  C.  arenatus,  147.  Types  of 
the  sub-genera,  148.  311.  C.  dor- 
miter, fossil,  149. 

Coralliophaga,  259.  376. 

Corals,  growth  of,  65. 

Corbis,  Lam.,  371. 

Corbula,  367. 

Coriocella,  235.  355. 

Coronaxis,  147.  311.  Types  of  the 
sub-genera  of,  148. 

Costellaria,  form  of,  320. 

Cowries,  61.  63.  324.  Analogy  of 
Cyprfficassis  to,  ^67.  The  Cyprse- 
inae,  typical,  135,  324. 

Crabs,  with  bivalve  shells,  52. 

Crassatella,  369. 

Crassina,  Lam,,  372. 

Crassispira,  characters  of,  152.  313. 

Creator,  works  of  the,  perfect,  42. 


410 


INDEX. 


Crenatula,  385. 

Crepidula,  230,  231.  Natural  sta- 
tion of,  239.  355. 

Cryptoconchus,  zone  of,  247.  358. 

Cryptostoma,  235. 

Cuma  sulcata,  87.  307. 

Cumingia,  370. 

Cunicula  planeata,  cuneata,  and 
purpurata,  268.  378. 

Cuttlefish,  description  of  the,  5. 
Eyes  of  the,  8.  Mode  of  swim- 
ming, 31.  Food  of,  34.  Organ!, 
sation  of,  38.  Extinct  tribe  of, 
fossil,  4S. 

Cuvier,  baron,  character  of  his 
Jtegne  Animal  with  regard  to  the 

.  Mollusca,  16.  His  Memuires  on 
the  Testacea,  20.  System  of,  25. 
35.  54.  211.  Definitions  in  Grif- 
fith's, 53. 

Cyclas,  257.  3fi9. 

Cyclinae,  sub-family,  369. 

Cyclobranchia,  comprehend  Patella 
and  Chiton,  25.  55.  United  by 
Cuvier  to  Dithyra,  54,  Con- 
struction of,  58.  246.  357. 

Cvclocantha,  with  a  circle  of  spines, 
215.  348. 

Cyclocotyles,  external  parasites,  46. 

Cyclonassa,  genus,  69.  300. 

Cyclophora,  186.  ooQ. 

Cyclops,  a  genus  of  crabs,  52. 

Cyclostoma,  56.  171.  198.  336.  Its 
analogy  to  Pupa,  169.  Mouth, 
characters  of,  185.  207.  Discoid 
form  of,  227. 

Cyclotus,  of  Guilding,  186.  336. 

Cylindrella,  description  of,  135.326. 

Cyllene,  the  genus  characterised, 
81.  305.  Approximates  to  Pseud- 
oliva,  82, 

Cymbiola,  muricated,  101.  105.  317. 
Sub-typical,  126.  Types  of  this 
genus  represent  those  of  Voluta, 
117.  Tableof  analogies,  118.  C. 
ve.spertilio,  106.  318.  C  tubercu- 
lata,  118.     C.  Braziliensis,  118. 

Cymbium,  104.  117. 

Cyprffia,  of  Linnteus,  61.  100.  324. 

Cyprfecassis,  C)5.  Analogy  to  cow- 
ries, 67.  ;  and  to  the  Nassina?,  70. 
Characters  of,  298. 

CyprzEidc-c,  affinities  of,  59.  61.  Shell 
described,  63.  Analogies  to  be 
traced  from  the  animals  only, 
115.  n.  1.35.     Family  of,  324. 

Cyprseinte,  typical  forms,  1-35.  324. 

Cyprajlla,  structure  of,  325. 

Cypraaova,  525. 

Cypricardia,  257. 

Cyrena,  370. 

Cytherca,  372. 


Decadopecten,  388. 

Delphinula,  215.  348. 

Diagram  of  the  athnitics  of  Muri- 
cida?  and  Turbinellidse,  95. 

Dianchora,  388. 

Diceras,  375. 

Dipsas,  of  Leach,  263.  288. 

Discodoma,  its  circumference  cari- 
nated,  192.  329. 

Dithyra,  the  Aristotelian  term  for 
bivalves,  13.  Considered  ana- 
tomically, 29.  No  apparent  head 
or  eyes  in,  53.  All  bivalves  are 
marine  or  fluviatile,  33.  Food  of, 
53.  Sub-typical,  35,  36.  Circle 
of,  45.  Analogies  of,  49.  256. 
Survey  of  the  order,  254.  Gene- 
ralisation, 290.  Arrangement  of 
the  order,  ,361. 

Dolabella,  251.  359. 

Dolium,  e,6.  299. 

Donax,  259.  373. 

Doridium,  252.  360. 

Doris,  24,  25.  37.  250.  Has  naked 
branchia,  54. 

Dove  shells,  137. 


E. 


Ear-shells,"see  Haliotis. 

Earth-worms,  their  body  disposed 
in  rings,  7.  Resemblances  of,  to 
the  eel,  7. 

Eburna,  types  of,  81,  82.  structure, 
306. 

Eburninte,  base  truncated  and 
notched,  76.  Sub-family  of,  81. 
Genera  and  analogies  of,  83.  Af- 
finities of,  95,  96.  Definition  of, 
305. 

Echinella,  sub-genus  of  Trochus, 
207.  221.352. 

Echinidaj,  shells  of  the,  7.  Ten- 
tacula  lof,  7.  Slow  locomotion 
of,  7. 

Echinorynchus,  46. 

Echinus,  the,  its  conformation,  7. 

Elenchus,  219,  220.  351. 

Emarginula,  58.  240.  Characters 
of,  243,  244.  356. 

Enomphalus,  fossil,  196. 

Ensatella,  365. 

Epistyia  conica,  165.  331. 

Erato,  135.  326.  Unites  the  Cypras- 
idiB  and  Volutida?,  326.  n. 

Eruca,  Sid.,  .334. 

Erycina,  259.  The  name  pre-occu- 
pied,  370. 

Eryx,  instead  of  Erycina,  371. 

Ethcria,  237.  390. 

Etheridie,  family  of,  390.  Remark- 
able affinities  of  this  group,  257. 


INDEX. 


411 


Eulima,  343. 

Eyes,  of  the  Testacea,  8.  53.  97. 
Of  the  Cephalopoda,  8. 


Fasciolje,  37.  Cup-shaped 'suckers 
of  the,  38.     Food  of,  46.  " 

Fasciolaria,  76.  P4.  Characters,  303. 

Ferussac,  baron  de,  his  work  on 
the  terrestrial  Mollusca,  IS.  171. n. 

Ficula,  characters  of,  85.  307.  F. 
caudata,  85.    F.  rapa,  85. 

Firula,  46. 

Fishes,  the  Cephalopoda,  among  the 
Mollusca,  bear  greatest  resem- 
blance to,  51. 

Fissurella,  58.  62.  240.  Description 
of,  243.  555, 356. 

Fistulana,  363. 

Foot  or  belly  of  molluscous  animals, 
30.  134. 

Foraminata,  cephalopodous,  43. 
.Foraminifera,  investigated  by  the 
microscope,  44.    Organisation  of, 
45. 

Fossils,  arguments  founded  on 
those  of  testaceous  genera  now 
extinct,  40.  Those  of  the  larger 
reptiles,  41 .  Of  Cephalopoda,  48. 
Of  Turbinellins,  77.  Of  Cones, 
149.    Snails,  196. 

Fragella.'Sw.,  352. 

Freshwater  and  fluviatile  Testacea, 

ctct 

Fusing,  or  spindle-shells,  76.  87.  90. 
154.  Delicate  and  elegant,  89. 
Analogies  of  Pyrulinffi:;to,  92. ;  of 
Turbellinfe  to,  93.  Sub-genera 
of,  308. 

Fusus,  the  typical  genus,  87.  90. 
308.  Fossil,  77.  F.  bulbiformis, 
90.  F.  ficulneus,  colossus,  coro- 
natus,  91.  F.  col  us,  96.  Affinities 

;  of  this  group,  154.  F.  strombi- 
formis,  typical,  154.  F.  Syracu- 
sensis,  154. 


G. 

Galeomma,  257.  376. 

Gasteropoda,  of  Lamarck,  24.  Of 
Cuvier,  25.  Anatomy  of  the,  29. 
Progression  of,  30.  Eyes  and 
head  of,  o3.  Phytophagous,  33. 
The  spiral  univalves  eminently 
typical,  34.  47.  Developement 
of  the  perfect  spire,  gradual,  47. 
Analogies  with  the  rest  of  the 
animal  kingdom,  49.  Primary 
divisions,  53.  Analogies  of  the 
Muricin£e  and  Turbinellidfe,  53. 
Of  Gasteropoda  and  Testacea,  60. 


Of  the  zoophagous  and  phyto- 
phagous classes.  111.  160. 195.228. 
Aberrant  tribes  of,  2-39.  Analogies 
of  phytophagous  and  carnivorous, 
242. 

Gasteropteron,_248.  252.362. 

Gastrochina,  2o/.  363. 

Generation  of  Mollusks,  29.  292. 

Generalisation,  remarks  on,  290. 

Geographic  distribution  of  Tes- 
tacea, 34. 

Geology,  its  relations  with  con- 
chology,  9.  12.  Fossils  of  the 
Paris  basin,  77.  Of  Hordwell 
Cliff,  77. 

Geomitra,  Terrestrial,  166.  332. 

Geotrochus,  conical  spire  of,  165. 
331,  332.    Sub-genera  of,  166. 

Geovula,  group  of,  208.  344. 

Gervillia,  385. 

Gibberula,  Sw.,  323. 

Glabella,  133.  324. 

Glauconome,  366. 

Globularia,  345. 

Glycimeris,  369. 

Gnathodon,  370. 

Gonidomus,166.  332. 

Gonospira,  168.  333. 

Goniostoma,  177-  181.  535. 

Gryphffia,  389. 

Guilding,  Rev.  Lansdown,  on  the 
Mollusca  of  the  Caribbean  Seas, 
17.  182.  Drawings  by,  18.  n.  ISO. 
Discoveryof  Herpaby,  45.  Draw- 
ing of  a  species  of  Nassa,  69. 


H. 


Haliotidffi,  the,  111.  556,  354.  Con- 
formation of,  159.  228.  Circular 
group  of  the, 231. 

Haliotidea,  Stv.,  354. 

Haliotis,  or  ear-shell,  25.  30.  Cha- 
racters of.  111.  230.  354.  The 
animal,  229.     H.  asinina,  231- 

Harpa.  the  harp-shells.  66.  298. 

Harpiila,  genus,  102.  134  317.  H. 
vexillum,  71.106.119.  H.hebrsea, 
106.  H.  fulminata,  107,  108.  119. 
12.5.  H.  bullata,  107. 119.  H.  ly- 
riformis,    107-    119.      H.  costata, 

119.  H.  nucleus,  119.  H.  poly- 
zonata,  119.  H.  musica,  119.  H. 
sulcata,  119.  H.  Lapponica,  120. 
Mr.  Broderip's  Observations  on 
H.  dubia,  120.  n.  Sub-generic 
types,    120.    122.     Analogies    of, 

120.  122. 

Harpula  costata  and  multicostata, 

119.  121. 
Haustellaria,  296. 
Hectocotyles,  of  Cuvier,  46. 
Helicell^,  164.  194.  Their  disk-like 

shells,  16-1.  333.  Broad-lipped,  191. 


412 


INDEX. 


Helicidffi,  analogies  of,  111.  Land 
and  freshwater  snails,  158.  Prin- 
ciples of  investigating  this  tribe, 

160.  291.  The  only  division  of 
Testacea  breathing  atmo.'^pheric 
air,  161.  Circular  group  of,  161. 
Network  of  pulmonary  vessels  in, 

161.  Tentacula  of,  161.  Chief 
families  described,  162.  186.  Ana- 
logies of,  162.  227.  Sub-families 
of,  162.    Classification  of,  326. 

Helicinje,  or  testaceous  snails,  56. 

162.  330.  336.  Are  typical,  163. 
Group  extensive,  184.  194. 

Helicogena,  of  Ferussac,  191. 
Helisoma,  337. 

Helix  proper,  description,  164,  165. 
227.  330.  H.  hortensis,  164.  Ana- 
logies of,  166.  Sub-genera  of,  166. 
Hemicardium,373. 
Hemicycla,  164. 193. 
Hemidbnta,  288.  381. 
Hemifusus,  91.  94. 
Hemimactra,  369. 
Hemimitra,  199. '342. 
Hemiodon,  genus,  191.  330.  Toothed 

aperture  of,  164.  194. 
Hemisinus,  200.  341. 
Hemitoma,  sub-genus,  244.  356. 
Hemitrochus,  with  elevated  spire, 

165.  331. 
Herpa,  genus  of  soft  MoUusca,  dis- 
covered by  Guilding,  18.  45.  161. 
189.  327.    App.  405. 
Heteropoda,    divided    into     Cari- 
naria,   Pterotrachia,  and  Phylli- 
roe,  25.     By  Cuvier,  into  Firoles 
and  the  Carinariae,  25.  48. 
Hiatula,  101.  132.  322. 
Hinnites,  388. 

Hipponyx,  31.  58.  240.  244.  357. 
Hippopus,  47.  257.  374. 
Horce   Entomologicce,  notes  on  the 

Testacea  in  the,  19. 
Humphrey,  George,  F.L.S.,  system 
of   conch ology  by,   15.     His  ar- 
;    rangement    compared    tabularly 
with    Lamarck's,    20.    Order  I., 
Marine  Testacea,  20.     Order  II., 
Fluviatile,  21.     Order  III.,  Ter- 
restrial, 21.     His  enumeration  of 
univalves,  22. 
Hybrids,  non-production  of,  292. 
Hyria,   its  connection  with   Unio, 

264.  285.  380. 
Hyria  avicularis,  263.  278.     H.  cor- 

rugata,  263.  284. 
Hyridella,  380. 

Hyrina?,     sub-family  of,   282.  378. 
.Analogies  of,  285. 


lanthina,  or  oceanic  snail, '31.  195. 

Inferobranchia,  of  Cuvier,  25. 

Infusoria,  4. 

Inoceramus,  385. 

Intestina,  heterogeneous  class  of, 
37.  45. 

Iridea,  its  affinity  to  Mysca,  283. 

.    Remarks  on,  284.  379. 

Iridinina,  257.  262.  380.  Prox- 
imate to  Anodon,  264.  Typical 
species  of,  286.  I.  Nilotica,  286. 
I.  elongata,  291. 

Iridinina;,  sub-faraily,  286.  380. 

Isocardia,  374. 


J. 


Johnson,  Dr.,  of  Edinburgh,  his 
valuable  labours  on  the  soft  Mol- 
lusca,  43.  n. 


K. 

Klein,  'his  ornithological  cabinet, 
9.  11.  Conchological  labours  of, 
14. 


L, 

Lacuna,  241. 

Lffivicardium,  373. 

Lamarck,  his  arrangement  of  the 
Testacea,  15,  16.  26.  Compara- 
tive Tables,  20.  First  Order  of 
Lamarck :  Conchiferes  dimyaires, 
22.;  tenuipedes,  22.;  lamelli- 
pedes,  23.  ;  ambigus,  23.  His  se- 
cond  order  :  Conchiferes  mono, 
myaires,  23.  :  Branchiopoda,  23. 
His  division  of  MoHusca  into  five 
orders,  23.  ;  Pteropoda,  23.  ; 
Gasteropoda,  24. ;  Trachelipodes, 
24  ;  Cephalopodes,  24. ;  Hetero- 
poda, 25. 

Lamprodoma,  132.  225.  321. 

Lamproscapha,  genus,  287.  381. 

Lamprostoma,  350. 

Lanistes,  384. 

Lanites,  339. 

Latiaxis,  82.  306. 

Ligumia  recta,  291." 

Leiodomus,  69.  74.  302. 

Leiostoma,  analogies  of,  192.     Cha- 
racters of,  308.  328. 

Leiostomus,  90.  94. 

Leptolimnea,  338. 

Leptoconus,  312. 


INDEX. 


413 


Lepton,  of  Turton,  366. 

Leptospira,  176. 337. 

Leucostoma,  173.  336. 

Ligumia,  2t;8.  274.  378. 

Lima,  257.  387. 

LimaciiiEB,    162.   329.     Sub-family, 

189. 
Limax,  the  genus,  10.  45.  189.  327. 

Food    of,    S3.     Respiration,    56. 

160.    First  germ  of  limaciform 

structure,  161.  Arrangement,  327- 
LimnEea,  Sec,  see  Limninse. 
Limnjeus,   description  of,  187.    L. 

stagnalis,  189. 
Liianinee,   spiral    fluviatile    shells, 

162.  187.  337.     Analogies  of,  162. 

188.  339. 
Limpets,  the  structure  and  habits 

of,  25.  30,  31. 60.  239.  355.  Fresh- 

water,  188. 
Linnajus,  error  of,  9.     Simplicity 

of  his  nomenclature,  14.     System 

of,  15.     On  multivalves,  28. 
Lister's  Conchology,  14. 
Lithodomus,  384. 
Littorina,  or  Turbines,  206. 
Loligo,  51. 
Loripes,  of  Poli,  371. 
Lowe,  of  the  Mollusca  of  Madeira, 

18. 
Lucernellfe,  191.  193.  329,  330. 
Lucerninae,  or  lamp-snails,  163.  186. 

190.  328.      Circle  of  affinity   of 

the,  194. 
Lucerninte,  or  terrestrial  volutes, 

162. 
Lucidella,  192.  194.  330. 
Lucidula,  329. 
Lucina,  371. 

Lucternin®,  analogies  of,  192. 
Lutraria,  368. 
Lymnadia  alata,  280.     Genus,  266. 

267.  280.  379. 
Lyrostoma,  329. 


M. 

Macrodontes,  182.  334. 

Macrospira,  168. 171.  335. 

Macrotrachia,  typical,  255,256.  362. 
Analogies  of,  258. 

Mactra,  257.  368. 

Mactridffl.  259. 

Malacology  treats  both  of  shells  and 
their  inhabitants,  13.  Recent  in- 
quiries as  to  the  nature  of  the 
animals,  97.  Theory,  292.  Glos- 
sary, 391. 

Malleus,  385. 

Mamillaria,  .345. 

Man,  the  Caucasian  race  said  to  be 
the  typical  form  of,  116. 

Margafitana,  288,  289.  3S2. 

Marginalis,  278,  279. 


Marginella,  97.  323.  ' 
Marginellinffi,  or  date-shells  98..10L 

OJ.   OZ.J. 

Martesia,  364. 

Medusse,  the,  appertains  to  the  Ra- 
diata,  5. 

Megadesma,  370. 

Megadomus,  cardinal  teeth  of,  266. 
269.  378.     M.  gigas,  266.  275. 

Megalomastoma,  186.  336, 

Melacantha,  341. 

Meladomus,  340. 

Melafusus,  202.  341. 

Melampus,  182.  Semi-aquatic,  196. 
Guiiding's  remarks  upon,  208. 
Amphibious  volutes,  34.3,344. 

Melania,  47. 59. 158.  341.  The  true, 
199.  Sub-genera :  Melacantha, 
Potadoma,  Hemisinus,  Melanella, 
199.  340,  341.  M.  lineata,  200. 
Analogies  of,  201. 

Melanianee,  or  black  snails,  157. 159. 
195.  340.  Genera  of,  201.  203. 
210. 

Melanithes,  fossil,  202.341. 

Melanopsis,  59. 198.  200.  341.  Minor 
types  diversified,  201.  Analogies 
of  sub-genera  of,  203. 

Melanopsides.  of  Ferussac,  204. 

Melatoma,  202.  342. 

Melons,  or  typical  volutes,  67.  99. 
105.  111.  Considered  as  a  sub- 
genus, 116,  117. 

Menostoma,  of  Blainville,  46. 

Microtoma,  74.  301. 

Mitra,  the  mitre-shells,  97,  98.  Ty- 
pical, 126.  129.  318.  Analogies, 
130.  M.  sanguisuga,  98.  M.  epis- 
copalis,127,128.  M.zonata,  128.  n. 
M.  terebrans,  131.  M.  rutiina 
punctata,  131.     M.  lactea,  131. 

Mitranze,  sub-family,  31S.  Spire 
acute  in,  98.  Characteristics  of, 
99.  101.  126.  Real  type  of,  112. 
Analogies  of,  129. ;  to  the  Strom- 
bidte,  154. 

Mitrella,  101.  128, 129.  321. 

Mitreola,  127.  n.  129.  320. 

Modiola,  bivalve,  257.  384. 

Mollusca,  the,  or  soft  animals,  1. 
Their  appearance  unprepossess- 
ing, 2.  Division  of  the  groups  of, 
3.  Devoid  of  internal  bone,  4. 
Nervous  system  of,  variable,  4. 
Their  three  divisions  character- 
ised, 7.  Their  arrangement  in 
respect  to  the  circle  of  affinities, 
8.  Lister's  arrangement  of,  9. 
Mistakes  in  recognising  the  true, 
10.  On  the  testaceous,  26,  ei  seq. , 
see  Testacea.  The  parasitic,  44. 
The  Cephalopoda  most  resemble 
fishes,  51.  Analogies  of  testaceous 
Mollusca  to  Annulosa,  52.  Gas- 
teropoda possess  an  aortic  heart, 


4U 


INDEX. 


54.  General  principles  of  inves- 
tigating, 54.  97.  Naked  mollusks 
among  the  Helicidffi,  161. 

Monilea,  220.  352. 

Monoceros,  100.  Tooth-like  pro- 
cess of,  301. 

Monodonta,  212.  217—219.  362. 
Analogies' of,  226.  Characters  of, 
220. 

Monophora,  38. 

Monothyra,  of  Aristotle,  13. 

Mulleria,  257. 

Multi valve  shells,  21.  28.  399. 

Murex,  the,  63.  295.  Vitulinus,  64. 
68.  Magellanicus,  harp-like,  65. 
68. 

Muricanthus,  structure  of,  296. 

Muricidse,  64.  295.  Sub-families, 
89.  99.  Diagram  of  affinities  of, 
95.     Analogies  of,  112. 

Muricinae,  or  whelks,  63.  Circle  of 
the,  64.  89.  Sub-families  of,  67. 
Shortness  of  their  canal,  75.  Cha- 
racters  of,  295. 

Muricidea,  296. 

Muscle,  the,  or  Mytilus,  31.  383. 

Mva,  257.  367.  M.  margaritifera, 
261. 

Myadae,  family  of,  257-  260.  367. 

IMycetopus,  380. 

Myocliama,  375. 

Myristica,  307.     M.  coronata,  8S. 

Mysca,  sub-genus,  276.  283.  378. 
Analogies  of  types  of,  278.  M. 
nasuta,  2&3.  M.  ovata,  263.  277. 
292.  Structure  of,  266.  M.  [lic- 
torum,  278.  282.  Aberrant  spe- 
cies of,  285. 

Mytilus,  31.383. 

N. 

Na'ia,  sub-genus,  284.  379.  N.  elon- 
gata,  286. 

Naidea,  276. 

Nassa,  typical  distinction  of,  68. 
300. 

Nassiiiae,  sub-family  of,  63.  69.  299. 
Circle  of.  70.  Analogies  of,  70. 
112.     Affinities,  95,  96. 

Natica,  234.  241.  345. 

Nattcaria,  346. 

Naticella,  animal  of,  249.  345. 

NaticidiB,  family  of,  60.  235.  344. 
Analogies  of,  111.  Structure  of 
the  nerits,  159. 

Naticinas,  sub-family,  241.  345. 

Nature,  on  the  works,  provisions, 
and  devices  of,  41.  Her  ascend- 
ing scale  from  imperfection  to 
perfection,  42.  44.  Great  circle 
of  the  system  of,  3.  40.  49,  et  seq. 
Tenacious  of  her  laws,  115. 
Modes  of  (levelopement  of  animal 
forms,  161.  293. 


Nautilus,  the,  39. 
Navicella,  347. 
Nebularia,  319. 
Nematura,  197.340. 
Nerita,  346. 
Neritinae,  347- 
Neritopsis,  346. 

Nervous  system  of  shell-fish,  29. 
Nitidella,  151.  153.  313. 
Nomenclature,  remarks  on,  92.  291. 
Notarchus,'.251.  359. 
Novaculina,  S65. 
Nucula,  257.  259.  382. 
Nudibranchia,    naked    animals    so 
termed,  6.  25.   35.     Description, 

36.  50.     Respiratory    organs    of, 

37.  The  tribe  distinct,  40. 


O. 


Oligyra,  337. 

Oliva,  97.  132.  321. 

Olivella,  324.     O.  biplicata,  82.  132. 

322.  n. 
OlivincE,  98.132.321. 
Onchid«,  marine,  56. 
Onchidium,  190.  327. 
Oniscia,  67-  70.  299. 
Onustus,  or  carriers,  212.  217-  221. 

355.    O.  agglutinans,  222. 
Orbis,  fossil,  196. 
Ostrffia,  affinities   of  the,  47.  257. 

387—389. 
Ostridffi,  the,  257.  385. 
Ovula,  135.  325. 

OvuliuEe,  or  egg-shells,  135.  325. 
Oyster,  the,  27.  387.      The   river 

oysters,  369. 


Pachylabra,  339. 

Pachvtoma,  337- 

Pagodella,  2u7.  219.  351. 

Paludina,  genus,  197.  339. 
para,  197.  P.  impura, 
parvula,  198. 

Paludomus,  198. 

Pandora,  3o8. 

Pa!,o])ia,  367. 

Papyridea,  374. 

Parenchyniata,  affinitie-s  of  the, 
4.  n.  Intestinal  Testacea,  35. ; 
and  worms,  38.  Parasitic  Mol- 
lusca,  44.  Cuvier's  second  fa- 
mily; habits  and  food,  46.  Ana- 
logy with  annulose  Vermes,  52. 

Parmophorus,  58.  62.  243.  356. 

Partula,  of  Ferussac.  179.  n. 

Parella,  or  limpet,  25.  30.  47-  58. 
357.  Nearly  stationary,  31.  234. 
240.     Adhesion  to  rocks,  244. 

Patularia,  287.  381. 


P.  vivi- 
198.     P. 


Proper,  199.  340. 


1.3 


INDEX. 


415 


Pecteii,  257.  259.  387,  388. 

Pectinibranchia,  comprehend  Tro- 
chus,  Turbo,  and  many  univalve 
marine  Testacea,  25.  55. 185. 

Pectunculus,  383. 

Pedipes,  2C8.  344. 

Pedicularia,  240.  245.  357. 

Pedum,  388. 

Periwinkle,  27-    Food  of  the,  33. 

Perna,  385. 

Persicola,  133.  323.  •' 

Petricola,  257.  376. 

Phakellopleura,  358. 

Phasianella,  207.213.  354. 

Pholadomya,  365. 

Pholas,  its  residence,  32.  Power  of 
enlargingtheir  cave  in  rocks,  &c., 
32.  257.        Of  LinncBus,  36:3. 

Pholidffi,  257.  362. 

Pholida?a,  36i. 

PhvUidea  and  Diphyllidea,  25,  58. 
248.  250.  358. 

PhyllidiniE,  sub-family,  249.  358. 

Phyllonotus,  296. 

Physa,  187.  338. 

Phytophaga,  Lamarck's  subdivi- 
sions of,  24.  Food  of  phyto- 
phagous gastropods,  33.  55.  Or- 
ganisation of,  56.  Sexes,  56.  Re- 
spiration, 56.  Confines  of,  with 
the  Zoophaga,  59.  Point  of  union 
with  Zoophaga,  158.  Primary 
divisions  of  the  phytophagous 
shell-fish,  158.    Families  of,  160. 

Picidae,  262. 

Pileolus,  347. 

Pileopsis,  357. 

Pinnfe,  or  wing-shells,  31.  387. 
Byssus.  or  silken  tuft  of,  32. 

Pirena,  156,  157. 

Pithohelix,  16i,  165. 

Placuna,  389,  390. 

Placunomia,  390 

Plagiostoma,  388. 

Planarite,  the,  possess  no  branchia, 
28.  Form  of,  37.  Analogy  of 
naked  slugs  with,  4.5.     Fossil,  196. 

PlanaridEe,  true,  swim  freely,  46. 

Planaxis,  59.  198.  342.  Animal  of, 
204. 

Planorbis,  55.  164.  186.  227.  337. 
P.  covneus,  187.  I 

Plant-like  animals,  4.  n.  5. 

Pleurobrancliaana,  361. 

Pleurobranchinje,  sub-family,  361. 

Pleurobranchus,  248.  252.  361. 

Pleuronectia,  388. 

Pleurotoraa,  136. 154.  314. 

PleurotomariEe,  213.  223.  353. 

PleurotoraiuEe,  or  slit-shells,  137. 
152.314.  Affinities  of,  154  Cu- 
rious analogies  of,  155,  156. 

Plicadomus,  352. 

Pli'-atella,  78.  304. 

Plicatula,  389. 


Poll,  investigations  of,  16. 

Polvdontes,  329. 

Polygyra,  330. 

Polypes,  or  Arcita,  4.  Polypes  char- 
nues,  6.    Tunicated,  6. 

Polytropa,  80.  P.  crispata,  81. 
Structure  described,  305. 

Porcina,  104. 

Potadoma,  199.  200.  341. 

Potomida,  genus,  137.  276.  281.  316. 

^379.  P.  corrugata,  281,  282.  P. 
elongata,  282.  P.  littoralis,  282. 
289.     P.  Batava  and  Sicula,  282. 

Potomis,  156.  158.  315. 

Potomophila,  188.  338. 

Priapulis,  6. 

Processes  for  capturing  prey,  34. 
Of  the  Xudibranchia,  37. 

Progression  or  locomotion  of  shell- 
fish, 30.  134 

Psammobia,  259. 370. 

Pseudoliva,  82.  306.  Ps.  plumbea, 
loo. 

Psittacidffi,  262. 

Pterocera,  typical  of  the  Strom- 
binae,  1,38.  310.  P.  lambis,  138. 
P.  millipeda,  138.  P.  sinuata,  138. 
Analogy  of  the  types  of  form  of 
the  genus,  144.  P.'latissimus,  144. 

Pteronotus,  296. 

Pteropoda,  of  Lamarck,  23.  Of 
Cuvier,  25.  No  apparent  head 
or  eyes,  33.  First  tribe  of  Cepha- 
lopoda, 48. 

Ptilota,  eminently  typical,  51. 

Pulmonaria.  25.  55.  208. 

Pulvinites,  SS5. 

Puncticulis,  311. 

Pupa,  inquiry  into  pupaceous  shells, 
161.  163.  Description  of,  164.  Cy. 
lindrical,  maggot-shaped,  167.  183. 
332.  The  sub-genera,  168.  Ana- 
logy of  Cyclostoma  to,  169.  j  of 
Clausilia  with,  184. 

Pupella,  183.  .334. 

Purpura,  63.  74  204.  P.  lapillus, 
and  imbricatus,  80.  P.  coronata, 
301. 

Purpurinse,  or  purpuras,  63.  300. 
How  far  resembling  Buccininje, 
71.  Analogies  of  Pyrulinas  and, 
73.     Affinities,  95.  204. 

Pusia,  320. 

Pusiodon,  Sw  ,  330. 

Pusiostoma,  150. 152. 220.  313.   ; 

Pustularia,  324. 

Pyramidea,  225.  350. 

Pyramidella,  343. 

Pyrella  spirilla,  77.  304. 

Pyrena,  315. 

Pyrula  of  modern  authors,  83.  Its 
shape,  84.  P.  perversa,  84.  P. 
myristica,  86.    P.  hippocastanum, 

86.  P.  lineata,  86.     P.  carnaria, 

87.  Characters  of,  307. 


416 


INDEX. 


Pyrulinse,  genera  described,  73.  88. 
307.  Characteristics  of  the  pear- 
shells,  76.  83.  Resemblances  to 
Purpurinas,  88. ;  to  Fusinje,  92. 


Quadrupeds,  analogical '  compari- 
sons of  Gasteropoda^with,  49. 

Quoy,  M.,  new[shells  discovered  by, 
17- 196.  His  researches  in  testa- 
ceous animals,  17.  156.  204.  Leio- 
domus  of,  69.  His  plates  valuable, 

,    128. 


Radiata,  the  second  class  of  Mol. 
lusoa,  5.  Nerves  of,  radiated,  5. 
Destitute  of  eyes,  8.  Analogies 
of,  52. 

Ranella,  64.  297. 

Rapella,  82.  307. 

Reniella,  386. 

Reproduction,  modes  of  testaceous, 
29.  54. 

Reptilia,  analogy  of  Nudibranchia 
with,  50. 

Respiration  of  Testacea,  &c.,  29. 55. 
Siphonic  organ  of,  55.  111. 

Rhinoclavis,  157.  315. 

Rhinodomus,  80.  305. 

Rhodostoma,  208.  346. 

Ricinula,  72.  Planospira,  73.  Cha- 
racters of,  300. 

Rimula,  243.  356.    Z 

Rissoa,  343. 

Rostellaria,  138.  310.  Elegance  of 
their  form,  140.  R.  rectirostris,  of 
great  rarity,  141.  146.  R.  curvi- 
rostris,  141.  R.  fissurella,  141. 
R.  columbata,  141.  R.  raacro- 
ptera,  144.  R.  cancellatus,  146. 
R.  canalis,  146.  Analogies  of  the 
group,  145.     Species  of,  145. 

Rotella,  213.  222.  227.  353. 

RotelliuEe,  213. 222.  353. 

Rotifera,  are  prototypes  of  the  Ra- 
diata, 4.  n. 


Sanguinolaria,  366. 

Saxicava,  376. 

Saxicavidae,  257.  259.  375. 

Scabricola,  319. 

Scalaria  pretiosa,  82.  185.  343.  Cir- 
cular mouth  of,  207. 

Scaphella,  genus,  100.  Types  of, 
12.J.  318.  Connection  with  V' olu- 
tilithes,   124.    Forms  a  circular 


group,  125.  S.  maculata,  101.  S. 
fulgetrum,'  101.  S.  fusiformis, 
103.  108.  123.  S.  papillaris,  103. 
108.  S.undulata,  107.  123.  S.  pa- 
pulosa, 108.  123.: 

Scaphula,  132.  322. 

Scarabus,  196.  208,  209.  344. 

Schizodesma,  368. 

Scissurella,  209.  344.  Sowerby's  fi- 
gures  of,  209. 

Scolyminffi,  75.  78.  The  circle  of, 
perfect,  81.  95.  Classification  of 
the  genera,  304. 

Scolymus,  77.  115.  S.  umbilicaris, 
80.  Characters  and  species  of, 
304. 

Scorpions,  observation  on,  .53. 

Scutibranchia,  of  Cuvier,  25.  47. 
358.  Respiration  of  the,  57.  In- 
ternal structure,  57.  60.  239. 
Divisions  of,  240.     Circle  of,  245. 

Sea  eggs,  or  Echinida,  5. 

Senectinee,  or  snake.shells,212. 214. 
3i8.     Analogies  of,  224. 

Senectus,  206.  213.  Species  of,  215. 
348. 

Shells  and  shell-fish, 2, f^se^.^tudy 
of,  important  to  geology,  9. 
Science  looks  to  the  animal  rather 
than  its  shelly  domicile,  10.  On 
what  principle  cabinets  should  be 
arranged,  10.  Modifications  of 
the  forms  of,  11.  New  shells  im- 
ported, 17.  Habits  of  the  animals 
investigated,  17.  Desiderata  as 
to  plates  representing,  19.  Divi- 
sions and  analogies  of,  26.  Struc- 
ture of,  27.  Locomotion  of,  30. 
Permanent  habitat  of,  32.  River, 
33.  Land,  33.  56.  Gastropod,  53. 
Spiral,  62.  The  Helicidas  de- 
scribed, 160.  Marine,  195.  206. 
River  bivalves,  259.  et  passim. 
Systematic  arrangement  of,  295. 
Explanation  of  terms,  391. 

Sigaretus,  animal  of  the,  229.  234. 
241.  345.    Sigaret  of  Tonga,  235. 

Siliquaria,  362. 

Siphonaria,  58.  245.  357. 

Siphonostoma,  333. 

Skin,  of  Testacea,  resembles  a  man- 
tle, 29. 
Slugs,  terrestrial  and  fluviatile,  fi5. 
SO.  Description  of,  35.  45.  55. 
Mantle  of,  56.  Respiration  of,  5&. 
Structure  of,  162.  Oceanic,  238. 
Classification  of,  327. 
Snails,  account  of,  25.  55.  164.  Uni- 
valve, 27.  Head  and  eyes  of,  3.3. 
Food  of,  33.  Minute  testaceous, 
described,  45.  Respiratory  per- 
foration in  the  mantle,  56.  Land 
and  fresliwatcr,  59.  1.58.  The 
pre-eminent  type  of  phytopha- 
gous Gasteropoda,  160.    Families 


INDEX. 


417 


arranged,  162.  See  Helix  and 
Helicidje.  The  lamp  snails,  190. 
Oceanic,  31.  195.210,  etseq.  Clas- 
sification of,  326.  328. 

Solarium,  213.  217.  221.  352. 

Solan,  365. 

Solenella,  366. 

Soleninse,  sub-family,  365. 

Solenocurtis,  366. 

Solenymia,  366. 

Spiders,  observation  on,  53. 

Spirorbis,  337. 

Spondylus,  32.  388. 

Starfish,  of  the  class  Radiata,  5. 

Stenopsis,  of  Guildiiig,  328. 

Stenopus,  190.  The  animal  figured 
190. 

Stomatella,  231.    S.  duplicata,  233. 

Stomatia,  229.  Description  of,  230. 
354.  Types  of,  231.  Analogies 
of,  232.  234. 

Streptaxis,  165  331. 

Strepsidura,  90.  94.  308. 

Strigatella,  131.  319. 

Strombidffi,  have  fully  developed 
eyes,  33.  47.  55.  Wing-shells, 
63.  Respiratory  siphon  of.  111. 
Predacious,  136.  Sub-families 
of,  143.  Typical  genera  of,  152. 
156.  309.     Analogies  of,  154. 

Strombidea,  138.  140.  146.  310. 

Strombinae,  true  wing-shells,  138. 
309.  Genera  of,  138,  139.  145. 
Affinities  of,  138.  142.  Analo- 
gies of,  140.  143. 

Strombus,  tuberculated,  116.  Lobe 
of  the  genuine,  121. 123.  Typical 
of  the  class,  136.  S.  pes-pelicani, 
137.  141.  S.  sinuatus,  138.  S. 
latissimus,  138.  S.  melanosto- 
mus,  139.  S.  pacificus,  139.  S. 
gigas,  pink-mouthed,  139.  144. 
S.  granulatus,  139.  S.  goliathus, 
the  largest  lip  of  the  genus,  1,39. 
S.  gibberulus,  140.   144.      S.  Lu- 

.  huanus,  140.  143.  S.  Auris- 
Dianffi,  139.  144,  145.  S.  sue- 
cinctus,  144.  S.  lentiginosus,  139. 
144.  Analogies  of  the  types  of 
the  genus,  145.  The  strombi- 
form  structure,  a  primary  type, 
154.  310. 

Struthiolaria,  81.  Relation  to  Mu- 
rex,  83.    Characters  of,  306. 

Stuchbury,  Mr.,  71.  n. 

Succinea,  190.  189.  328. 

Sun-shells,  216. 

Swimming  of  molluscous  animals, 
31. 

Symphynota  compressa,  280.  287. 

Systematic  and  natural  arrange- 
ment; forming  Part  II.  of  this 
work,  295. 


Tzenio'ides  of  Cuvier,  compr.ehended 
in  the  annulose  circle,  44. 

Tape-worms,  44. 

Tectibranchia,  comprehend  Bulla 
and  Aplysia,  25.  35.  Form  and 
habits  of,  36.  Shells  hid  in  the 
flesh,  55.     Natural  group  of,  58. 

247.  Naked  order  of,  236.  Ana- 
logies of,  237.  Representations 
of,  238.  Circular  succession  and 
analogies   of,   clearly  developed, 

248.  Classification  of,  361. 
Tellina,  371. 

Tellinidse,  260.  369. 

Tellininfe,  sub-family,  370. 

Terebellum,  137.  146.  310. 

Terebra,  302.  Long  spire  of  the 
group,  74.  131.  T.  vittata,  74. 
T.  maculata,  302. 

Terebralia,  157.  315. 

Terebratulfe,  32.  Processes  of,  to 
capture  prey,  34. 

Teredina,  364. 

Teredo,  257.  364. 

Terms  used  in  conchology,  391. 

Testacea,  the,  3.  Are  a  popularly 
interesting  class  of  molluscous 
animals,  3.  The  typical  Testacea 
provided  with  eyes,  8.  The  most 
perfect  of  the  Mollusca,  8.  Ar- 
rangement of  species  of,  9.  Groups 
of  the  typical,  as  discriminated 
by  Aristotle,  13.  Arrangement  of, 
by  various  modern  naturalists,  41, 
cl  seq.  Of  the  Caribbean  seas, 
17.  Difference  of  the  animals 
confirms  the  recognised  charac- 
teristics of  their  shells,  18.  Na- 
tural disposition  of  the  class,  19. 
Table  of,  20.  Order  I.,  the  Ma- 
rine, 20.  Order  11.,  the  Fluvi- 
atile,  21.  Order  III.,  Terrestrial, 
21  Merits  of  Lamarck  and  Cu- 
Tier's  classifications  of,  26.  Ana- 
logies of,  26.  Typical  character, 
istics  of,  27. ;  positive  and  ne- 
gative, 28.  Considered  anato- 
mically,28.  Blood  white,  28. ;  its 
circulation  double,  29.  Respir- 
ation, 29.  55.  Reproduction,  29. 
54,  Deglutition,  29.  Operculum, 
97.  Nervous  system  of,  29.  Mode 
of  progression  of,  30.  Power  of 
saltation,  30.  Adhesion,  31.  De- 
fect of  power  of  locomotion,  32. 
Perforation  of  a  permanent  re- 
sidence, 27.  32.  Some  cemented 
to  fixed  or  floating  substances,  32. 
Head,  eyes,  and  tentacula  of,  33. 
Habits,  food,  and  geographic  dis- 
tribution, 33,  -34.  97.  Primary 
divisions  of,  35.  Gigantic  genera 
of,  known  only  from  tradition,  39. 


E    E 


418 


INDEX. 


Great  circle  of,  44.  46.  Orders 
of,  49.  Analogies  of,  52.  A  single 
grand  genus,  Testacea,  imagined, 
92.  Families  of  exquisite  spiral, 
97.    Series  of  fluviatile,  204.  &c. 

Testacella,  327. 

Tethys,  24,  25. 

Textilia  312. 

Thallepus,  251.  359.  T.  ornatus, 
251.*n. 

Thallicera,  196.  339.  T.  avellana, 
196.     Analogies  of,  210. 

Theliconus,  312. 

Theliderma,  268.  272.  377.  T. 
irrorata,  nodosa,  '  cylindrica, 
pustulata,  plicata,  272.  T.  cylin- 
drica, 274.  T.  Peruviana,  276. 
Analogies  of  the  sectional  types 
of,  273. 

Thelidomus,  191.  194.  Description 
of,  228.  332.  353. 

Thelidonta,  193,  194. 

Thracia,  376. 

Tiara,  typical  form,  97.  319.  322. 
Real  type  of  Mitrina,  112.  129. 
Analogies  of,  130.  319.  T.  tere- 
brans, 131.    Sub-genera  of,  320. 

Tiarella,  131.  319. 

Timorenla,  38. 

Tomella,  155.  314. 

Tornatella,  207.  343. 

Trachelipoda,  of  Lamarck,  24. 

Tremadotes  of  Rudolphi,  46. 

Trichopodus,  211. 

Tridacna,  257.  374. 

Trigonia,  383. 

Triphorus,  342. 

Triton,  genus,  24,  25.  The  naked, 
31.  Swims  in  search  of  its  prey, 
34.  Description  of,  36.  50.  64. 
297.    T.  clandestinum,  75. 

Tritonidea,  74.  Remarks  upon  cha- 
racters of,  74.  302. 

Trivea,  135.  325. 

Trochatella,  337. 

Trochella,  59.355. 

Trochia,  74.  302. 

Trochidae,  are  marine,  159.  211. 
Genera  of,  207.  Habits  of,  212. 
Shells  perlaccous,  212.  Pyra- 
midal, 212.  Sub-families  of,  213. 
Analogies  with  those  of  Turbi- 
dae,  223.  ;  with  the  Achatinse, 
226.     Family  of,  347. 

Trochidon,  351. 

Trochin«,  described,  213.  Oper- 
culum horny,  216.  Genera  and 
analogies  of,  224.  Sub-family, 
349. 

Trochus,  of  LinnjEus,  25.  350,  351. 
Spiral,  47.  Horny  onorculum  of, 
213.  T.  Niloticus,  216.  T.  zizy- 
phinu?,  218.  T.  merula,  219. 
Strawberry,  220.  Analogies  of, 
226. 


Tropics,  the,  Testacea  of,  34.  1 47. 

Truncatella,  analogies  of,  209.  343.' 

Tubicanthus,  349. 

Tubulibranchia,  comprehend  Ver- 
metus,  Magilis,  and  Sihquaria, 
25.     Structure  of,  36.  47.  54.  134. 

?  256.  Characters  of  the  tribe,  258. 
Systematic  arrangement  of,  361. 

Tuliparia,  311. 

Turbidee,  family  and  circle  of,  44. 
341.  The  animals  alone  offer  the 
characters  of,  160.  Shells  spiral, 
with  an  operculum,  and  without 
pearly  lustre,  195.  Typical  ge- 
nera of,  223. 

Turbinffi,  or  winkles,  195.  Analo- 
gies of,  210.  Characters  of  the 
genera,  342. 

Turbinelia,  tyi)ical  genus,  76.  94. 
303.  Fossil  Clavalithes,  77.  T. 
Scolymus,  78.    T.  rapa,  78. 

Turbinellidae,  characteristics  of 
shell  of,  75.  303.  Sub-families  of, 
75.  243.  Sub-typical  group,  spiny 
and  coronated,  115.  Analogies 
to  the  Cassidffi,  89.  Affinities  to 
the  Muricidffl,  95. 

Turbinellinfe,  'smooth  and  heavy 
shells  of,  75.  Analogies  of  Fusinae 
and,  93.     Arrangement,  &c.,303. 

Turbo,  of  Linnfeus,  animal  of,  25. 
207.  345.  Phytophagous  and  also 
zoophagous,  47.  Possesses  a  si- 
phon, 160.  206.  Figure  of,  207. 
T.  sarmaticus,  213.  .T.  Nicoba- 
ricus,  222. 

Turritella,  resemblance  with  Tere- 
bra,  74.  131.  A  typical  genus, 
206.  Long-spired,  223.  Charac- 
ters of,  343. 


U. 

Umbrella,  62.  253.  361. 

Ungulina,  259.371.  ^ 

Unio  circulus,  261.     U.  gigas,  26^.  ^ 

275.  U.  margaritifera,  263.  U. 
ciuieatus,  263.  U.  Esopus,  263. 
271.  U.  mytiloides,  268.  270,  271. 
292.  U.  torsus,  270.  U.  recta, 
268.    272.     U.    cylindricus,    273. 

276.  U.  alata,  279.  U.  nasutus, 
279.  U.  truncatus,  270.  U.  no- 
dosa, 270.  U.  obliqua,  270.  U. 
rugosus,  273.  U.  elongata,  275. 
U.  radiatus,  276.  U.  marginata, 
278.  U.  frat;ilis,  279.  U.  Austra- 
lis,  285.  The  typical,  264.  Its 
umbones,  or  bosses,  265.  Distinct 
types  of,  268.  377.  Analogies  of 
sub-genera  of,  269.  274.  Climate 
inhabited  by,  283. 

Unionidae,  the,  257.  260.  264.  282.  n. 
Primary  divisions  of,  264.  377. 


INDEX. 


419 


Principle  of  variation  in  these 
shells,  262.  Modifications  of,  290. 
Station  of  the  family  of,  262. 
Analogies  of  the  genera  of,  267. 
Inexhaustible  profusion  of,  292. 

Unionins,  the,  265.  Characters  of, 
275.  377.     Analogies  of,  285. 

Uniopsis,  figure  of,  288. 382.  U.  ra- 
diata,  289. 

Univalve  sheli-fish,  21.  27.  30.  Spi- 
ral, 34.  et  passim. 


Valvata,  185.  196.  198.  339. 

Velotes,  347. 

Velutina,  235.  355. 

Veneriuce,  sub-family,  371. 

"Venerupes,  376. 

Venus,  372. 

Vermes,  annulose  or  intestinal,  27. 
44.  52.  True,  completely  articu- 
lated, 38. 

Vermetus,  362. 

Vermillia,  362. 

Vertebrata,  allusions  to  the,  1.  2.  4. 
116.  Connecting  link  of  the  Mol- 
lusca  with  the  Cephalopoda,  or 
cuttlefish,  5,  6.  33.  Theory  re- 
specting the,  42 — 44.  50.  Circle 
of  the,  49. 

Vertego,  183. 

Vesica,  360. 

Vexilla,  69.  300. 

Vitrella,  360. 

Vitrina,  190.  328. 

Vitularia,  297. 

Voluta,  of  Linnaeus,  316.  V.  zebra, 
101.  V.  olla,  102.  V.  Neptuni, 
104.  113.  116.  V.  angulata,  105. 
V.  magnifica,  105.  V.  mitis,  105. 
V.ancilla,  106.  V.  scapha,  105. 
V.  fulgetrum,  108.  124.  Generic 
character,  a  large  spire,  108.  Af- 
finities and  distribution,  101 — 111. 
Generic  types  of  this  genus,  113. 
316.  Circles  of,  113.  Analogies 
of,  114.  V.  imperialis,  and  bat 
volutes,  114.  Coronated  volutes, 
115.  Melons,  or  typical  volutes, 
67.  t9.  105.  ni.  117.  V.  Brode- 
ripia  remarks  upon,  105.  117.  V. 
Cymbium,  104.  117.  V.  ^thi- 
opica,  117.  V.  musicalis,  122.  V. 
fulgens,  125.  The  terrestrial  vo- 
lutes, 162.  190.  192. 
Volutella,  323. 

Volutidse,  or  volutes,  6.3.  76.    Pri- 
mary groups  of,  98. 112.   Analogy 


to  Zoophaga,  99.  117.  ;  and  Cas- 
sida;,  100.  Circle  of  affinity  per. 
feet,   101.     Analogy  of  Volutince 

_  with,  112. ;  of  the  Muricidce  with, 
112.  General  analogies  of,  132. ; 
to  vertebrated  and  annulose  ani- 
mals, 134.     Classification  of,  316. 

Volutilithes,  genus,  105.  112.  318. 
Typical  conformation  of,  121.  V. 
musicata,  115.  V.  costaria,  121. 
125.  V.  angulata,  122.  V.  ci- 
thera,  122.  V.  rafispina,  123,  124. 
Analogies  of,  122.  Sub-generic 
types  of,  122.  318. 

Volutins,  are  the  typical  volutes, 
98.  316.  Genera  of,  112.  Ana- 
logies of,  112.  122.  129. 

Volvaria,  134.  326. 

Vulsella,  386. 


w.    ■ 

Wentle-trap,  common,  207. 

West  Indies,  Testacea,  &c.  of  the, 
17.  45.  180.  182.  192.  209. 

Wheel-shells,  213. 

Winkles,  or  Turbinse,  195. 

Wood's  Catalogue,  19. 

Worms,  red-blooded,  7,  44.  Gas- 
tropod, 33. 


Xylophaga,  364. 


Z. 

Zoanthus,  a  genus  connected  with 
Radiata,  6. 

Zonites,  177.  227.  331. 

Zoology,  arranged  on  a  new  basis,  3. 
Aristotle  established  the  first  prin- 
ciples of,  13. 

Zoophaga,  the,  perfection  of  sight 
of,  8.  Table  of,  24.  Carnivorous 
shell-fish,  55.  Respiratory  siphon 
of,  55.  Eyes  and  tentacula,  55. 
Mouth,  55.  Tongue,  56.  Sexes, 
56.  Operculum,  56.  Genera  of, 
56.  Distinctions  of,  59.  61.  Di- 
visions of,  62.  83.  97.  Analogies 
of,  99.  Point  of  union  with  the 
tribe  Phytophaga,  1.58.  Families 
of,  160.    The  tribe  arranged,  295. 

Zoophytes,  the  true  Acritaare  con- 
sidered as  compound,  4.  n. 


THE    END. 


London : 
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